pypdfium2 is an ABI-level Python 3 binding to PDFium, a powerful and liberal-licensed library for PDF rendering, inspection, manipulation and creation.

It is built with ctypesgen and external PDFium binaries. The custom setup infrastructure provides a seamless packaging and installation process. A wide range of platforms is supported with pre-built packages.

pypdfium2 includes helpers to simplify common use cases, while the raw PDFium API (ctypes) remains accessible as well.

python -m pip install -U pypdfium2

If available for your platform, this will use a pre-built wheel package, which is the easiest way of installing pypdfium2. Otherwise, setup code will run. If your platform is not covered with pre-built binaries, this will look for system pdfium, or attempt to build pdfium from source.

pdfium-binaries also offer V8 (JavaScript) / XFA enabled builds. If you need them, do e.g.:

PDFIUM_PLATFORM=auto-v8 pip install -v pypdfium2 --no-binary pypdfium2

This will bypass wheels and run setup, while requesting use of V8 builds through the PDFIUM_PLATFORM=auto-v8 environment setting. See below for more info.

As of this writing, pypdfium2 does not require any mandatory runtime dependencies, apart from Python and PDFium itself (which is commonly bundled).

However, some optional support model / CLI features need additional packages:

• Pillow (module PIL) is a pouplar imaging library for Python. pypdfium2 provides convenience adapters to translate between raw bitmap buffers and PIL images. It also uses PIL for some command-line functionality (e.g. image saving).
• NumPy is a library for scientific computing. As with Pillow, pypdfium2 provides helpers to get a numpy array view of a raw bitmap.
• opencv-python (module cv2) is an imaging library built around numpy arrays. It can be used in the rendering CLI to save with pypdfium2's numpy adapter.

pypdfium2 tries to defer imports of optional dependencies until they are actually needed, so there should be no startup overhead if you don't use them.

Note, unlike helpers, pypdfium2's setup is not bound by API stability promises, so it may change any time.

System

• C pre-processor (gcc/clang – alternatively, specify the command to invoke via $CPP)
• git (Used e.g. to determine the latest pdfium-binaries version, to get git describe info, or to check out pdfium on sourcebuild. Might be optional on default setup.)
• slsa-verifier (if using pdfium-binaries; optional)

Python

• ctypesgen (pypdfium2-team fork)
• setuptools >= v70.1.0

Python dependencies should be installed automatically, unless --no-build-isolation is passed to pip.

git clone "https://github.com/pypdfium2-team/pypdfium2.git"
cd pypdfium2/

# In the pypdfium2/ directory
python -m pip install -v .

This will invoke pypdfium2's setup.py. Typically, this means a binary will be downloaded from pdfium-binaries and bundled into pypdfium2, and ctypesgen will be called on pdfium headers to produce the bindings interface.

pdfium-binaries offer SLSA provenance to verify authenticity, so it is highly recommended that you install the slsa-verifier in this case.

If no pre-built binaries are available for your platform, setup will look for system pdfium, or attempt to build pdfium from source.

• -v: Verbose logging output. Useful for debugging.
• -e: Install in editable mode, so the installation points to the source tree. This way, changes directly take effect without needing to re-install. Recommended for development.
• --no-build-isolation: Do not isolate setup in a virtual env; use the main env instead. This renders pyproject.toml [build-system] inactive, so setup deps must be prepared by caller. Useful to install custom versions of setup deps, or as speedup when installing repeatedly.
• --no-binary pypdfium2: Do not use binary wheels when installing from PyPI – instead, use the sdist and run setup. Note, this option is improperly named, as pypdfium2's setup will attempt to use binaries all the same. If you want to prevent that, set e.g. PDFIUM_PLATFORM=fallback to achieve the same behavior as if there were no pdfium-binaries for the host. Or if you just want to package a source distribution, set PDFIUM_PLATFORM=sdist.

PDFIUM_PLATFORM="system-search" python -m pip install -v .

Look for a system-provided pdfium shared library, and bind against it.

Standard, portable ctypes.util.find_library() means will be used to probe for system pdfium at setup time, and the result will be hardcoded into the bindings. Alternatively, set $PDFIUM_BINARY to the path of the out-of-tree DLL to use.

If system pdfium was found, we will look for pdfium headers from which to generate the bindings (e.g. in /usr/include). If the headers are in a location not recognized by our code, set $PDFIUM_HEADERS to the directory in question.

Also, we try to determine the pdfium version, either from the library filename itself, or via pkg-config. If this fails, you can pass the version alongside the setup target, e.g. PDFIUM_PLATFORM=system-search:XXXX, where XXXX is the pdfium build version. If the version is not known in the end, NaN placeholders will be set.

If the version is known but no headers were found, they will be downloaded from upstream. If neither headers nor version are known (or ctypesgen is not installed), the reference bindings will be used as a last resort. This is ABI-unsafe and thus discouraged.

If find_library() failed to find pdfium, we may do additional, custom search, such as checking for a pdfium shared library included with LibreOffice, and – if available – determining its version.
Our search heuristics currently expect a Linux-like filesystem hierarchy (e.g. /usr), but contributions for other systems are welcome.

There is also a system-generate:$VERSION target, to produce system pdfium bindings in a host-independent fashion. This will call find_library() at runtime, and may be useful for packaging.

Further, you can set just system to consume pre-generated files from the data/system staging directory. See the section on caller-provided data files for more info.

You can also install pypdfium2 with a self-compiled pdfium shared library, by placing it in data/sourcebuild/ along with a bindings interface and version info, and setting the PDFIUM_PLATFORM="sourcebuild" directive to use these files on setup.

This project comes with two scripts to automate the build process: build_toolchained.py and build_native.py (in setupsrc/pypdfium2_setup/).

• build_toolchained is based on the build instructions in pdfium's Readme, and uses Google's toolchain (this means foreign binaries and sysroots). This results in a heavy checkout process that may take a lot of time and space. By default, this script will use vendored libraries, but you can also pass --use-syslibs to try to use system libraries. An advantage of the toolchain is its powerful cross-compilation support (including symbol reversioning).
• build_native is an attempt to address some shortcomings of the toolchained build (mainly a bloated checkout process, and lack of portability). It is tailored towards native compilation, and uses system tools and libraries (including the system's GCC compiler), which must be installed by the caller beforehand. This script should theoretically work on arbitrary Linux architectures. As a drawback, this process is not supported or even documented upstream, so it might be hard to maintain.

You can also set PDFIUM_PLATFORM to sourcebuild-native or sourcebuild-toolchained to trigger either build script through setup. However, for simplicity, both scripts/subtargets share just sourcebuild as staging directory.

Dependencies:

• When building with system libraries, the following packages need to be installed (including development headers): freetype, icu-uc, lcms2, libjpeg, libopenjp2, libpng, libtiff, zlib (and maybe glib to satisfy the build system).
• You might also want to know that pdfium bundles agg, abseil, fast_float.
• When building with system tools, gn (generate-ninja), ninja, and a compiler are needed. If available, the compiler defaults to GCC, but Clang should also work if you set up some symlinks and make sure you have the libclang_rt builtins installed.

To do the toolchained build, you'd run something like:

# call build script with --help to list options
python setupsrc/pypdfium2_setup/build_toolchained.py
PDFIUM_PLATFORM="sourcebuild" python -m pip install -v .

Or for the native build, on Ubuntu 24.04, you could do e.g.:

# Install dependencies
sudo apt-get install generate-ninja ninja-build libfreetype-dev liblcms2-dev libjpeg-dev libopenjp2-7-dev libpng-dev zlib1g-dev libicu-dev libtiff-dev libglib2.0-dev

# Build with GCC
python ./setupsrc/pypdfium2_setup/build_native.py --compiler gcc

# Alternatively, build with Clang
sudo apt-get install llvm lld
VERSION=18
ARCH=$(uname -m)
sudo ln -s "/usr/lib/clang/$VERSION/lib/linux" "/usr/lib/clang/$VERSION/lib/$ARCH-unknown-linux-gnu"
sudo ln -s "/usr/lib/clang/$VERSION/lib/linux/libclang_rt.builtins-$ARCH.a" "/usr/lib/clang/$VERSION/lib/linux/libclang_rt.builtins.a"
python ./setupsrc/pypdfium2_setup/build_native.py --compiler clang

# Install
PDFIUM_PLATFORM="sourcebuild" python -m pip install -v .

The native build may also work on Android with Termux in principle.

# set $PROJECTS_FOLDER accordingly
git config --global --add safe.directory '$PROJECTS_FOLDER/*'

pkg install gn ninja freetype littlecms libjpeg-turbo openjpeg libpng zlib libicu libtiff glib

# freetype
ln -s "$PREFIX/include/freetype2/ft2build.h" "$PREFIX/include/ft2build.h"
ln -s "$PREFIX/include/freetype2/freetype" "$PREFIX/include/freetype"
# openjpeg
OPJ_VER="2.5"  # adapt this to your setup
ln -s "$PREFIX/include/openjpeg-$OPJ_VER/openjpeg.h" "$PREFIX/include/openjpeg.h"
ln -s "$PREFIX/include/openjpeg-$OPJ_VER/opj_config.h" "$PREFIX/include/opj_config.h"

mv data/sourcebuild/libpdfium.cr.so data/sourcebuild/libpdfium.so

PY_VERSION="3.12"  # adapt this to your setup
LD_LIBRARY_PATH="$PREFIX/lib/python$PY_VERSION/site-packages/pypdfium2_raw"

pypdfium2 is like any other Python project in essentials, except that it needs some data files: a pdfium DLL (either bundled or out-of-tree), a bindings interface (generated via ctypesgen), and pdfium version info (JSON).

The main point of pypdfium2's custom setup is to automate deployment of these files, in a way that suits end users / contributors, and our PyPI packaging.

However, if you want to (or have to) forego this automation, you can also just supply these files yourself, as shown below. This allows to largely sidestep pypdfium2's own setup code.
The idea is basically to put your data files in a staging directory, data/system or data/sourcebuild (depending on whether you want to bundle or use system pdfium), and set the matching $PDFIUM_PLATFORM target to consume from that directory on setup.

This setup strategy should be inherently free of web requests. Mind though, we don't support the result. If you bring your own files, it's your own responsibility, and it's quite possible your pypdfium2 might turn out subtly different from ours.

# First, ask yourself: Do you want to bundle pdfium (in-tree), or use system
# pdfium (out-of-tree)? For bundling, set "sourcebuild", else set "system".
TARGET="sourcebuild"  # or "system"
STAGING_DIR="data/$TARGET"
# If you have decided for bundling, copy over the pdfium DLL in question.
# Otherwise, skip this step.
cp "$MY_BINARY_PATH" "$STAGING_DIR/libpdfium.so"
# Now, we will call ctypesgen to generate the bindings interface.
# Reminder: You'll want to use the pypdfium2-team fork of ctypesgen.
# It generates much cleaner bindings, and it's what our source expects
# (there are subtle API differences in terms of output).
# How exactly you do this is down to you.
# See ctypesgen --help or base.py::run_ctypesgen() for further options.
ctypesgen --library pdfium --rt-libpaths $MY_RT_LIBPATHS --ct-libpaths $MY_CT_LIBPATHS \
--headers $MY_INCLUDE_DIR/fpdf*.h -o $STAGING_DIR/bindings.py [-D $MY_FLAGS]
# Then write the version file (fill the placeholders).
# Note, this is not a mature interface yet and might change any time!
# See also https://pypdfium2.readthedocs.io/en/stable/python_api.html#pypdfium2.version.PDFIUM_INFO
# major/minor/build/patch: integers forming the pdfium version being packaged
# n_commits/hash: git describe like post-tag info (0/null for release commit)
# origin: a string to identify the build
# flags: a comma-delimited list of pdfium feature flag strings
#        (e.g. "V8", "XFA") - may be empty for default build
cat > "$STAGING_DIR/version.json" <<END
{
  "major": $PDFIUM_MAJOR,
  "minor": $PDFIUM_MINOR,
  "build": $PDFIUM_BUILD,
  "patch": $PDFIUM_PATCH,
  "n_commits": $POST_TAG_COMMIT_COUNT,
  "hash": $POST_TAG_HASH,
  "origin": "$TARGET-$MY_ORIGIN",
  "flags": [$MY_FLAGS]
}
END
# Finally, run setup (through pip, pyproject-build or whatever).
# The PDFIUM_PLATFORM value will instruct pypdfium2's setup to use the files
# we supplied, rather than to generate its own.
PDFIUM_PLATFORM=$TARGET python -m pip install --no-build-isolation -v .

This is a somewhat formal description of pypdfium2's setup capabilities. It is meant to sum up and complement the above documentation on specific sub-targets.

Disclaimer: As it is hard to keep up with constantly evolving setup code, it is possible this documentation may be outdated/incomplete. Also keep in mind that these APIs could change any time, and may be mainly of internal interest.

• Binaries are stored in platform-specific sub-directories of data/, along with bindings and version information.

• $PDFIUM_PLATFORM defines which binary to include on setup.

  • Format spec: [$PLATFORM][-v8][:$VERSION] ([] = segments, $CAPS = variables).
  • Examples: auto, auto:7269 auto-v8:7269 (auto may be substituted by an explicit platform name, e.g. linux_x64).
  • V8: If given, use the V8 (JavaScript) and XFA enabled pdfium binaries. Otherwise, use the regular (non-V8) binaries.
  • Version: If given, use the specified pdfium-binaries release. Otherwise, use the same version as the current pypdfium2 release. Set pinned to request that behavior explicitly. Or set latest to use the newest pdfium-binaries release instead.
  • Platform:
    • If unset or auto, the host platform is detected and a corresponding binary will be selected.
    • If an explicit platform identifier (e.g. linux_x64, darwin_arm64, ...), binaries for the requested platform will be used.²
    • If system-search, look for and bind against system-provided pdfium instead of embedding a binary. If just system, consume existing bindings from data/system/.
    • If sourcebuild, binary and bindings will be taken from data/sourcebuild/, assuming a prior run of the native or toolchained build scripts. sourcebuild-native or sourcebuild-toolchained can also be used to trigger either build through setup. However, triggering on the caller side is preferred as this allows to pass custom options.
    • If sdist, no platform-specific files will be included, so as to create a source distribution.

• $PYPDFIUM_MODULES=[raw,helpers] defines the modules to include. Metadata adapts dynamically.

  • May be used by packagers to decouple raw bindings and helpers, which may be relevant if packaging against system pdfium.
  • Would also allow to install only the raw module without helpers, or only helpers with a custom raw module.

• $PDFIUM_BINDINGS=reference allows to override ctypesgen and use the reference bindings file autorelease/bindings.py instead.

  • This is a convenience option to get pypdfium2 installed from source even if a working ctypesgen / C pre-processor is not available in the install env. May be automatically enabled under given circumstances.
  • Warning: This may not be ABI-safe. Please make sure binary/bindings build headers match to avoid ABI issues.

• To install

  With permanent channel config (encouraged):

  conda config --add channels bblanchon
  conda config --add channels pypdfium2-team
  conda config --set channel_priority strict
  conda install pypdfium2-team::pypdfium2_helpers

  Alternatively, with temporary channel config:

  conda install pypdfium2-team::pypdfium2_helpers --override-channels -c pypdfium2-team -c bblanchon -c defaults

  If desired, you may limit the channel config to the current environment by adding --env. Adding the channels permanently and tightening priority is encouraged to include pypdfium2 in conda update by default, and to avoid accidentally replacing the install with a different channel. Otherwise, you should be cautious when making changes to the environment.

• To depend on pypdfium2 in a conda-build recipe

  requirements:
    run:
      - pypdfium2-team::pypdfium2_helpers

  You'll want to have downstream callers handle the custom channels as shown above, otherwise conda will not be able to satisfy requirements.

• To set up channels in a GH workflow

  - name: ...
    uses: conda-incubator/setup-miniconda@v3
    with:
      # ... your options
      channels: pypdfium2-team,bblanchon
      channel-priority: strict

  This is just a suggestion, you can also call conda config manually, or pass channels on command basis using -c, as discussed above.

• To verify the sources

  conda list --show-channel-urls "pypdfium2|pdfium-binaries"
  conda config --show-sources

  The table should show pypdfium2-team and bblanchon in the channels column. If added permanently, the config should also include these channels, ideally with top priority. Please check this before reporting any issue with a conda install of pypdfium2.

Note: Conda packages are normally managed using recipe feedstocks driven by third parties, in a Linux repository like fashion. However, with some quirks it is also possible to do conda packaging within the original project and publish to a custom channel, which is what pypdfium2-team does, and the above instructions are referring to.

The authors of this project have no control over and are not responsible for possible third-party builds of pypdfium2, and we do not support them. Please use our official packages where possible. If you have an issue with a third-party build, either contact your distributor, or try to reproduce with an official build.

Do not expect us to add/change code for downstream-specific setup tasks, or to actively care about downstream packaging. Related issues or PRs may be closed without further notice if we don't see fit for upstream. Enhancements of general value that are maintainable and align well with the idea of our setup code are welcome, though. In case of doubt, open a discussion ticket and ask, but please don't expect much more than a "yes" or a "no".

If you are a third-party distributor, please point out in the description that your package is unofficial, i.e. not affiliated with or endorsed by pypdfium2 team.

Here are some examples of using the support model API.

• Import the library

  import pypdfium2 as pdfium
  import pypdfium2.raw as pdfium_c

• Open a PDF using the helper class PdfDocument (supports file path strings, bytes, and byte streams)

  pdf = pdfium.PdfDocument("./path/to/document.pdf")
  version = pdf.get_version()  # get the PDF standard version
  n_pages = len(pdf)  # get the number of pages in the document
  page = pdf[0]  # load a page

• Render the page

  bitmap = page.render(
      scale = 1,    # 72dpi resolution
      rotation = 0, # no additional rotation
      # ... further rendering options
  )
  pil_image = bitmap.to_pil()
  pil_image.show()

  Note, with the PIL adapter, it might be advantageous to use force_bitmap_format=pdfium_c.FPDFBitmap_BGRA, rev_byteorder=True or maybe prefer_bgrx=True, use_bgra_on_transparency=True, rev_byteorder=True, to achieve a pixel format supported natively by PIL, and avoid rendering with transparency to a non-alpha bitmap, which can slow down pdfium.

  With .to_numpy(), all formats are zero-copy, but passing either use_bgra_on_transparency=True (if dynamic pixel format is acceptable) or force_bitmap_format=pdfium_c.FPDFBitmap_BGRA is also recommended for the transparency problem.

• Try some page methods

  # Get page dimensions in PDF canvas units (1pt->1/72in by default)
  width, height = page.get_size()
  # Set the absolute page rotation to 90° clockwise
  page.set_rotation(90)
  # Locate objects on the page
  for obj in page.get_objects():
      print(obj.level, obj.type, obj.get_bounds())

• Extract and search text

  # Load a text page helper
  textpage = page.get_textpage()
  # Extract text from the whole page
  text_all = textpage.get_text_bounded()
  # Extract text from a specific rectangular area
  text_rect = textpage.get_text_bounded(left=50, bottom=100, right=width-50, top=height-100)
  # Extract text from a specific char range
  text_span = textpage.get_text_range(index=10, count=15)
  # Locate text on the page
  searcher = textpage.search("something", match_case=False, match_whole_word=False)
  # This returns the next occurrence as (char_index, char_count), or None if not found
  match = searcher.get_next()

• Read the table of contents

  import pypdfium2.internal as pdfium_i
  for bm in pdf.get_toc(max_depth=15):
      count, dest = bm.get_count(), bm.get_dest()
      out = "    " * bm.level
      out += "[%s] %s -> " % (
          f"{count:+}" if count != 0 else "*",
          bm.get_title(),
      )
      if dest:
          index, (view_mode, view_pos) = dest.get_index(), dest.get_view()
          out += "%s  # %s %s" % (
              index+1 if index != None else "?",
              pdfium_i.ViewmodeToStr.get(view_mode),
              round(view_pos, 3),
          )
      else:
          out += "_"
      print(out)

• Create a new PDF with an empty A4 sized page

  pdf = pdfium.PdfDocument.new()
  width, height = (595, 842)
  page_a = pdf.new_page(width, height)

• Include a JPEG image in a PDF

  pdf = pdfium.PdfDocument.new()
  image = pdfium.PdfImage.new(pdf)
  image.load_jpeg("./tests/resources/mona_lisa.jpg")
  width, height = image.get_px_size()
  matrix = pdfium.PdfMatrix().scale(width, height)
  image.set_matrix(matrix)
  page = pdf.new_page(width, height)
  page.insert_obj(image)
  page.gen_content()

• Save the document

  # PDF 1.7 standard
  pdf.save("output.pdf", version=17)

While helper classes conveniently wrap the raw PDFium API, it may still be accessed directly and is available in the namespace pypdfium2.raw. Lower-level utilities that may aid with using the raw API are provided in pypdfium2.internal.

import pypdfium2.raw as pdfium_c
import pypdfium2.internal as pdfium_i

Since PDFium is a large library, many components are not covered by helpers yet. However, as helpers expose their underlying raw objects, you may seamlessly integrate raw APIs while using helpers as available. When passed as ctypes function parameter, helpers automatically resolve to the raw object handle (but you may still access it explicitly if desired):

permission_flags = pdfium_c.FPDF_GetDocPermission(pdf.raw)  # explicit
permission_flags = pdfium_c.FPDF_GetDocPermission(pdf)      # implicit

For PDFium docs, please look at the comments in its public header files.⁴ A variety of examples on how to interface with the raw API using ctypes is already provided with support model source code. Nonetheless, the following guide may be helpful to get started with the raw API, if you are not familiar with ctypes yet.

• In general, PDFium functions can be called just like normal Python functions. However, parameters may only be passed positionally, i.e. it is not possible to use keyword arguments. There are no defaults, so you always need to provide a value for each argument.

  # arguments: filepath (bytes), password (bytes|None)
  # NUL-terminate filepath and encode as UTF-8
  pdf = pdfium_c.FPDF_LoadDocument((filepath+"\x00").encode("utf-8"), None)

  This is the underlying bindings declaration,⁵ which loads the function from the binary and contains the information required to convert Python types to their C equivalents.

  if hasattr(_libs['pdfium'], 'FPDF_LoadDocument'):
      FPDF_LoadDocument = _libs['pdfium']['FPDF_LoadDocument']
      FPDF_LoadDocument.argtypes = (FPDF_STRING, FPDF_BYTESTRING)
      FPDF_LoadDocument.restype = FPDF_DOCUMENT

  Python bytes are converted to FPDF_STRING by ctypes autoconversion. This works because FPDF_STRING is actually an alias to POINTER(c_char) (i.e. char*), which is a primitive pointer type. When passing a string to a C function, it must always be NUL-terminated, as the function merely receives a pointer to the first item and then continues to read memory until it finds a NUL terminator.

• First of all, function parameters are not only used for input, but also for output:

  # Initialise an integer object (defaults to 0)
  c_version = ctypes.c_int()
  # Let the function assign a value to the c_int object, and capture its return code (True for success, False for failure)
  ok = pdfium_c.FPDF_GetFileVersion(pdf, c_version)
  # If successful, get the Python int by accessing the `value` attribute of the c_int object
  # Otherwise, set the variable to None (in other cases, it may be desired to raise an exception instead)
  version = c_version.value if ok else None

• If an array is required as output parameter, you can initialise one like this (in general terms):

  # long form
  array_type = (c_type * array_length)
  array_object = array_type()
  # short form
  array_object = (c_type * array_length)()

  Example: Getting view mode and target position from a destination object returned by some other function.

  # (Assuming `dest` is an FPDF_DEST)
  n_params = ctypes.c_ulong()
  # Create a C array to store up to four coordinates
  view_pos = (pdfium_c.FS_FLOAT * 4)()
  view_mode = pdfium_c.FPDFDest_GetView(dest, n_params, view_pos)
  # Convert the C array to a Python list and cut it down to the actual number of coordinates
  view_pos = list(view_pos)[:n_params.value]

• For string output parameters, callers needs to provide a sufficiently long, pre-allocated buffer. This may work differently depending on what type the function requires, which encoding is used, whether the number of bytes or characters is returned, and whether space for a NUL terminator is included or not. Carefully review the documentation of the function in question to fulfill its requirements.

  Example A: Getting the title string of a bookmark.

  # (Assuming `bookmark` is an FPDF_BOOKMARK)
  # First call to get the required number of bytes (not units!), including space for a NUL terminator
  n_bytes = pdfium_c.FPDFBookmark_GetTitle(bookmark, None, 0)
  # Initialise the output buffer
  buffer = ctypes.create_string_buffer(n_bytes)
  # Second call with the actual buffer
  pdfium_c.FPDFBookmark_GetTitle(bookmark, buffer, n_bytes)
  # Decode to string, cutting off the NUL terminator (encoding: UTF-16LE)
  title = buffer.raw[:n_bytes-2].decode("utf-16-le")

  Example B: Extracting text in given boundaries.

  # (Assuming `textpage` is an FPDF_TEXTPAGE and the boundary variables are set)
  # Store common arguments for the two calls
  args = (textpage, left, top, right, bottom)
  # First call to get the required number of units (not bytes!) - a possible NUL terminator is not included
  n_chars = pdfium_c.FPDFText_GetBoundedText(*args, None, 0)
  # If no characters were found, return an empty string
  if n_chars <= 0:
      return ""
  # Calculate the required number of bytes (encoding: UTF-16LE again)
  # The function signature uses c_ushort, so 1 unit takes sizeof(c_ushort) == 2 bytes
  n_bytes = 2 * n_chars
  # Initialise the output buffer - this function can work without NUL terminator, so skip it
  buffer = ctypes.create_string_buffer(n_bytes)
  # Re-interpret the type from char to unsigned short* as required by the function
  buffer_ptr = ctypes.cast(buffer, ctypes.POINTER(ctypes.c_ushort))
  # Second call with the actual buffer
  pdfium_c.FPDFText_GetBoundedText(*args, buffer_ptr, n_chars)
  # Decode to string (You may want to pass `errors="ignore"` to skip possible errors in the PDF's encoding)
  text = buffer.raw.decode("utf-16-le")

• Not only are there different ways of string output that need to be handled according to the requirements of the function in question. String input, too, can work differently depending on encoding and type. We have already discussed FPDF_LoadDocument(), which takes a UTF-8 encoded string as char*. A different examples is FPDFText_FindStart(), which needs a UTF-16LE encoded string, given as unsigned short*:

  # (Assuming `text` is a str and `textpage` an FPDF_TEXTPAGE)
  # Add the NUL terminator and encode as UTF-16LE
  enc_text = (text + "\x00").encode("utf-16-le")
  # cast `enc_text` to a c_ushort pointer
  text_ptr = ctypes.cast(enc_text, ctypes.POINTER(ctypes.c_ushort))
  search = pdfium_c.FPDFText_FindStart(textpage, text_ptr, 0, 0)

• Leaving strings, let's suppose you have a C memory buffer allocated by PDFium and wish to read its data. PDFium will provide you with a pointer to the first item of the byte array. To access the data, you'll want to re-interpret the pointer as an array view with .from_address():

  # (Assuming `bitmap` is an FPDF_BITMAP and `size` is the expected number of bytes in the buffer)
  # FPDFBitmap_GetBuffer() has c_void_p as restype, which ctypes will auto-resolve to int or None
  buffer_ptrval = pdfium_c.FPDFBitmap_GetBuffer(bitmap)
  assert buffer_ptrval  # make sure it's non-null
  # Get an actual pointer object so we can access .contents
  buffer_ptr = ctypes.cast(buffer_ptrval, ctypes.POINTER(ctypes.c_ubyte))
  # Buffer as ctypes array (referencing the original buffer, will be unavailable as soon as the bitmap is destroyed)
  c_buffer = (ctypes.c_ubyte * size).from_address( ctypes.addressof(buffer_ptr.contents) )
  # Buffer as Python bytes (independent copy)
  py_buffer = bytes(c_buffer)

  Note that you can achieve the same result with ctypes.cast(ptr, POINTER(type * size)).contents, but this is somewhat problematic since ctypes used to cache pointer types eternally with Python < 3.14 (as size may vary, this can lead to memory leak like scenarios with long-running applications).

• Writing data from Python into a C buffer works in a similar fashion:

  # (Assuming `buffer_ptr` is a pointer to the first item of a C buffer to write into,
  #  `size` the number of bytes it can store, and `py_buffer` a Python byte buffer)
  buffer = (ctypes.c_char * size).from_address( ctypes.addressof(buffer_ptr.contents) )
  # Read from the Python buffer, starting at its current position, directly into the C buffer
  # (until the target is full or the end of the source is reached)
  n_bytes = py_buffer.readinto(buffer)  # returns the number of bytes read

• If you wish to check whether two objects returned by PDFium are the same, the is operator won't help because ctypes does not have original object return (OOR), i.e. new, equivalent Python objects are created each time, although they might represent one and the same C object.⁶ That's why you'll want to use ctypes.addressof() to get the memory addresses of the underlying C object. For instance, this is used to avoid infinite loops on circular bookmark references when iterating through the document outline:

  # (Assuming `pdf` is an FPDF_DOCUMENT)
  seen = set()
  bookmark = pdfium_c.FPDFBookmark_GetFirstChild(pdf, None)
  while bookmark:
      # bookmark is a pointer, so we need to use its `contents` attribute to get the object the pointer refers to
      # (otherwise we'd only get the memory address of the pointer itself, which would result in random behaviour)
      address = ctypes.addressof(bookmark.contents)
      if address in seen:
          break  # circular reference detected
      else:
          seen.add(address)
      bookmark = pdfium_c.FPDFBookmark_GetNextSibling(pdf, bookmark)

• In many situations, callback functions come in handy.⁷ Thanks to ctypes, it is seamlessly possible to use callbacks across Python/C language boundaries.

  Example: Loading a document from a Python buffer. This way, file access can be controlled in Python while the data does not need to be in memory at once.

  import os
  # Factory class to create callable objects holding a reference to a Python buffer
  class _reader_class:
    
    def __init__(self, py_buffer):
        self.py_buffer = py_buffer
    
    def __call__(self, _, position, buffer_ptr, size):
        # Write data from Python buffer into C buffer, as explained before
        buffer_ptr = ctypes.cast(buffer_ptr, ctypes.POINTER(ctypes.c_char * size))
        self.py_buffer.seek(position)
        self.py_buffer.readinto(buffer_ptr.contents)
        return 1  # non-zero return code for success
  # (Assuming py_buffer is a Python file buffer, e. g. io.BufferedReader)
  # Get the length of the buffer
  py_buffer.seek(0, os.SEEK_END)
  file_len = py_buffer.tell()
  py_buffer.seek(0)
  # Set up an interface structure for custom file access
  fileaccess = pdfium_c.FPDF_FILEACCESS()
  fileaccess.m_FileLen = file_len
  # Assign the callback, wrapped in its CFUNCTYPE
  fileaccess.m_GetBlock = type(fileaccess.m_GetBlock)( _reader_class(py_buffer) )
  # Finally, load the document
  pdf = pdfium_c.FPDF_LoadCustomDocument(fileaccess, None)

• When using the raw API, special care needs to be taken regarding object lifetime, considering that Python may garbage collect objects as soon as their reference count reaches zero. However, the interpreter has no way of magically knowing how long the underlying resources of a Python object might still be needed on the C side, so measures need to be taken to keep such objects referenced until PDFium does not depend on them anymore.

  If resources need to remain valid after the time of a function call, PDFium docs usually indicate this clearly. Ignoring requirements on object lifetime will lead to memory corruption (commonly resulting in a segfault sooner or later).

  For instance, the docs on FPDF_LoadCustomDocument() state that

  The application must keep the file resources |pFileAccess| points to valid until the returned FPDF_DOCUMENT is closed. |pFileAccess| itself does not need to outlive the FPDF_DOCUMENT.

  This means that the callback function and the Python buffer need to be kept alive as long as the FPDF_DOCUMENT is used. This can be achieved by referencing these objects in an accompanying class, e. g.

  class PdfDataHolder:
      
      def __init__(self, buffer, function):
          self.buffer = buffer
          self.function = function
      
      def close(self):
          # Make sure both objects remain available until this function is called
          # No-op id() call to denote that the object needs to stay in memory up to this point
          id(self.function)
          self.buffer.close()
  # ... set up an FPDF_FILEACCESS structure
  # (Assuming `py_buffer` is the buffer and `fileaccess` the FPDF_FILEACCESS interface)
  data_holder = PdfDataHolder(py_buffer, fileaccess.m_GetBlock)
  pdf = pdfium_c.FPDF_LoadCustomDocument(fileaccess, None)
  # ... work with the pdf
  # Close the PDF to free resources
  pdfium_c.FPDF_CloseDocument(pdf)
  # Close the data holder, to keep the object itself and thereby the objects it
  # references alive up to this point, as well as to release the buffer
  data_holder.close()

• Finally, let's finish this guide with an example how to render the first page of a document to a PIL image in RGBA color format.

  import math
  import ctypes
  import os.path
  import PIL.Image
  import pypdfium2.raw as pdfium_c
  # Load the document
  filepath = os.path.abspath("tests/resources/render.pdf")
  pdf = pdfium_c.FPDF_LoadDocument((filepath+"\x00").encode("utf-8"), None)
  # Check page count to make sure it was loaded correctly
  page_count = pdfium_c.FPDF_GetPageCount(pdf)
  assert page_count >= 1
  # Load the first page and get its dimensions
  page = pdfium_c.FPDF_LoadPage(pdf, 0)
  width  = math.ceil(pdfium_c.FPDF_GetPageWidthF(page))
  height = math.ceil(pdfium_c.FPDF_GetPageHeightF(page))
  # Create a bitmap
  # (Note, pdfium is faster at rendering transparency if we use BGRA rather than BGRx)
  use_alpha = pdfium_c.FPDFPage_HasTransparency(page)
  bitmap = pdfium_c.FPDFBitmap_Create(width, height, int(use_alpha))
  # Fill the whole bitmap with a white background
  # The color is given as a 32-bit integer in ARGB format (8 bits per channel)
  pdfium_c.FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF)
  # Store common rendering arguments
  render_args = (
      bitmap,  # the bitmap
      page,    # the page
      # positions and sizes are to be given in pixels and may exceed the bitmap
      0,       # left start position
      0,       # top start position
      width,   # horizontal size
      height,  # vertical size
      0,       # rotation (as constant, not in degrees!)
      pdfium_c.FPDF_LCD_TEXT | pdfium_c.FPDF_ANNOT,  # rendering flags, combined with binary or
  )
  # Render the page
  pdfium_c.FPDF_RenderPageBitmap(*render_args)
  # Get the value of a pointer to the first item of the buffer
  buffer_ptrval = pdfium_c.FPDFBitmap_GetBuffer(bitmap)
  assert buffer_ptrval, "buffer pointer value must be non-null"
  # Cast the pointer value to an actual pointer object so we can access .contents
  buffer_ptr = ctypes.cast(buffer_ptrval, ctypes.POINTER(ctypes.c_ubyte))
  # Re-interpret as array
  buffer = (ctypes.c_ubyte * (width * height * 4)).from_address(ctypes.addressof(buffer_ptr.contents))
  # Create a PIL image from the buffer contents
  img = PIL.Image.frombuffer("RGBA", (width, height), buffer, "raw", "BGRA", 0, 1)
  # Save it as file
  img.save("out.png")
  # Free resources
  pdfium_c.FPDFBitmap_Destroy(bitmap)
  pdfium_c.FPDF_ClosePage(page)
  pdfium_c.FPDF_CloseDocument(pdf)

pypdfium2 also ships with a simple command-line interface, providing access to key features of the support model in a shell environment (e. g. rendering, content extraction, document inspection, page rearranging, ...).

The primary motivation behind this is to have a nice testing interface, but it may be helpful in a variety of other situations as well. Usage should be largely self-explanatory, assuming a minimum of familiarity with the command-line.

Disclaimer: This project is provided on an "as-is" basis. This is not legal advice, and there is ABSOLUTELY NO WARRANTY for any information provided in this document or elsewhere in the pypdfium2 project, including earlier revisions. We disclaim liability for any possible damages resulting from using this license information. It is the embedder's responsibility to check on licensing. See also GitHub's disclaimer.

pypdfium2 itself is available by the terms and conditions of Apache-2.0 / BSD-3-Clause. Documentation and examples of pypdfium2 are licensed under CC-BY-4.0. pypdfium2 includes SPDX headers in source files. License information for data files is provided in REUSE.toml as per the reuse standard.

PDFium is available under "a BSD-style license that can be found in [its] LICENSE file" (see also BUILD_LICENSES/pdfium.txt for a copy in this repository).
Various other open-source licenses apply to dependencies included with PDFium. PDFium's license as well as dependency licenses have to be shipped with binary distributions.

pypdfium2 uses PDFium builds from the pdfium-binaries project, which is MIT-licensed as of this writing. pdfium-binaries auto-collect dependency licenses in a build-specific way. We extract these alongside the binaries, and include them in wheel packages / installations. There is also an aggregated BUILD_LICENSES/ directory for display in this repository.
Note that PDFium's dependencies might change over time. Please notify us if you think a relevant license is missing.

To the author's knowledge, pypdfium2 is one of the rare Python libraries capable of PDF rendering while not being covered by strong-copyleft licenses (such as the GPL).⁸

While using pypdfium2, you might encounter bugs or missing features. In this case, feel free to open an issue or discussion thread. If applicable, include details such as tracebacks, OS and CPU type, as well as the versions of pypdfium2 and used dependencies.

Roadmap:

• pypdfium2
  • Issues panel: Initial bug reports and feature requests. May need to be transferred to dependencies.
  • Discussions page: General questions and suggestions.
• PDFium
  • Bug tracker: Issues in PDFium. Beware: The bridge between Python and C increases the probability of integration issues or API misuse. The symptoms can often make it look like a PDFium bug while it is not.
  • Mailing list: Questions regarding PDFium usage.
• pdfium-binaries: Binary builder.
• ctypesgen: Bindings generator.

Given this is a volunteer open-source project, it is possible you may not get a response to your issue, or it may be closed without much feedback. Conversations may be locked if we feel like our attention is getting DDOSed. We may not have time to provide usage support.

The same applies to Pull Requests. We will accept contributions only if we find them suitable. Do not reach out with a strong expectation to get your change merged; it is solely up to the repository owner to decide if and when a PR will be merged, and we are free to silently reject PRs we do not like.

PDFium is inherently not thread-safe. See the API docs for more information.

As outlined in the raw API section, it is essential that Python-managed resources remain available as long as they are needed by PDFium.

The problem is that the Python interpreter may garbage collect objects with reference count zero at any time, so it can happen that an unreferenced but still required object by chance stays around long enough before it is garbage collected. However, it could also disappear too soon and cause breakage. Such dangling objects result in non-deterministic memory issues that are hard to debug. If the timeframe between reaching reference count zero and removal is sufficiently large and roughly consistent across different runs, it is even possible that mistakes regarding object lifetime remain unnoticed for a long time.

Although we intend to develop helpers carefully, it cannot be fully excluded that unknown object lifetime violations might still be lurking around somewhere, especially if unexpected requirements were not documented by the time the code was written.

As of this writing, PDFium's public interface does not provide access to the raw PDF data structure (see issue 1694). It does not expose APIs to read/write PDF dictionaries, streams, name/number trees, etc. Instead, it merely offers a predefined set of abstracted functions. This considerably limits the library's potential, compared to other products such as pikepdf.

PDFium's non-public backend would provide extended capabilities, including raw access, but it is written in C++, which (unlike pure C) does not result in a stable ABI, so we cannot use it with ctypes. This means it's out of scope for this project.

Also, while ABI bindings tend to be more convenient, they have some technical drawbacks compared to API bindings (see e.g. 1, 2)

The pypdfium2 codebase does not hard wrap long lines. It is recommended to set up automatic word wrap in your text editor, e.g. VS Code:

editor.wordWrap = bounded
editor.wordWrapColumn = 100

The pypdfium2 project uses the just command runner, which can be seen as a more modern, more flexible alternative to make. In particular, there's no good way to pass through positional arguments with make.

Run just -l (or open the justfile) to view the available commands.

pypdfium2 provides API documentation using Sphinx, which can be rendered to various formats, including HTML:

sphinx-build -b html ./docs/source ./docs/build/html/
just docs-build  # short alias

Built docs are primarily hosted on readthedocs.org. It may be configured using a .readthedocs.yaml file (see instructions), and the administration page on the web interface. RTD supports hosting multiple versions, so we currently have one linked to the main branch and another to stable. New builds are automatically triggered by a webhook whenever you push to a linked branch.

Additionally, one doc build can also be hosted on GitHub Pages. It is implemented with a CI workflow, which is supposed to be triggered automatically on release. This provides us with full control over build env and used commands, whereas RTD may be less liberal in this regard.

pypdfium2 contains a small test suite to verify the library's functionality. It is written with pytest:

python -m pytest tests/  # or `just test`

Note that ...

• you can pass -sv to get more detailed output.
• $DEBUG_AUTOCLOSE=1 may be set to get debugging information on automatic object finalization.

To get code coverage statistics, you may call

just coverage

Sometimes, it can also be helpful to test code on many PDFs.⁹ In this case, the command-line interface and find come in handy:

# Example A: Analyse PDF images (in the current working directory)
find . -name '*.pdf' -exec bash -c "echo \"{}\" && pypdfium2 pageobjects \"{}\" --filter image" \;
# Example B: Parse PDF table of contents
find . -name '*.pdf' -exec bash -c "echo \"{}\" && pypdfium2 toc \"{}\"" \;

The release process is fully automated using Python scripts and scheduled release workflows. You may also trigger the workflow manually using the GitHub Actions panel or the gh command-line tool.

Python release scripts are located in the folder setupsrc/pypdfium2_setup, along with custom setup code:

• update.py downloads binaries.
• craft.py builds platform-specific wheel packages and a source distribution suitable for PyPI upload.
• autorelease.py takes care of versioning, changelog, release note generation and VCS check-in.

The autorelease script has some peculiarities maintainers should know about:

• The changelog for the next release shall be written into docs/devel/changelog_staging.md. On release, it will be moved into the main changelog under docs/source/changelog.md, annotated with the PDFium version update. It will also be shown on the GitHub release page.
• pypdfium2 versioning uses the pattern major.minor.patch, optionally with an appended beta mark (e. g. 2.7.1, 2.11.0, 3.0.0b1, ...). Update types such as major or beta may be controlled via autorelease/config.json

In case of necessity, you may also forego CI and do the release locally, which would roughly work like this (though ideally it should never be needed):

• Run the autorelease script (this will implicitly switch onto the autorelease_tmp branch, make a release commit, and create the tag):

  python3 setupsrc/pypdfium2_setup/autorelease.py --register

• Merge the autorelease_tmp branch:

  git checkout main
  git merge autorelease_tmp

• Build the packages

  just packaging-pypi

• Push release commit/tag to the repository:

  git push
  git push --tags

• Upload to PyPI

  # this will interactively ask for your username/password
  twine upload dist/*

• Update the stable branch to trigger a documentation rebuild

  git checkout stable
  git rebase origin/main  # or: git reset --hard main
  git checkout main

If something went wrong with commit or tag, you can still revert the changes:

# perform an interactive rebase to change history (substitute $N_COMMITS with the number of commits to drop or modify)
git rebase -i HEAD~$N_COMMITS
git push --force
# delete local tag (substitute $TAGNAME accordingly)
git tag -d $TAGNAME
# delete remote tag
git push --delete origin $TAGNAME

Faulty PyPI releases may be yanked using the web interface.

pypdfium2 is used by popular packages such as langchain, docling, nougat, pdfplumber, and doctr.

This results in pypdfium2 being part of a large dependency tree.

• Benoît Blanchon: Author/Maintainer of PDFium binaries and patches.
• Yinlin Hu: pypdfium prototype and kuafu PDF viewer.
• Mike Kroutikov: Examples on how to use PDFium in redstork, redstork-ui and pdfbrain.
• Tim Head: Original idea for Python bindings to PDFium with ctypesgen in wowpng.
• Christian Heimes: RPM packaging for pdfium. Showing how to build pdfium natively without Google's toolchain.
• Adam Huganir: Help with maintenance and development decisions since the beginning of the project.
• kobaltcore: Bug fix for PdfDocument.save().
• Anderson Bravalheri: Help with PEP 517/518 compliance. Hint to use an environment variable rather than separate setup files.
• Bastian Germann: Help with inclusion of licenses for third-party components of PDFium.

... and further code contributors (GitHub stats).

If you have contributed to this project but are not mentioned here yet, please let us know.

The PDFium code base was originally developed as part of the commercial Foxit SDK, before being acquired and open-sourced by Google, who maintain PDFium independently ever since, while Foxit continue to develop their SDK closed-source.

pypdfium2 is the successor of pypdfium and pypdfium-reboot.

Inspired by wowpng, the first known proof of concept Python binding to PDFium using ctypesgen, the initial pypdfium package was created. It had to be updated manually, which did not happen frequently. There were no platform-specific wheels, but only a single wheel that contained binaries for 64-bit Linux, Windows and macOS.

pypdfium-reboot then added a script to automate binary deployment and bindings generation to simplify regular updates. However, it was still not platform specific.

pypdfium2 is a full rewrite of pypdfium-reboot to build platform-specific wheels and consolidate the setup scripts. Further additions include ...

• A CI workflow to automatically release new wheels at a defined schedule
• Convenience support models that wrap the raw PDFium/ctypes API
• Test code
• A script to build PDFium from source