| CARVIEW |
Select Language
HTTP/2 200
content-type: text/html
x-guploader-uploadid: AAwnv3L8whTm-YPYpIfSInebZkf3r9DoqtIlZBe_NhhWYq6xy9Hl-lXhSxMTJDIZSJeB0V0z
cache-control: public, max-age=3600
expires: Fri, 10 Oct 2025 20:58:37 GMT
last-modified: Fri, 10 Oct 2025 01:07:08 GMT
etag: W/"1444bfd4a97cea811434305038a8122e"
x-goog-generation: 1760058428831882
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 152543
x-goog-meta-goog-reserved-file-mtime: 1760057086
x-goog-hash: crc32c=4Nl95A==, md5=FES/1Kl86oEUNDBQOKgSLg==
x-goog-storage-class: STANDARD
accept-ranges: none
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
alt-svc: clear
referrer-policy: strict-origin-when-cross-origin
x-content-type-options: nosniff
strict-transport-security: max-age=63072000
content-security-policy: default-src 'self'; script-src 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; script-src-elem 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; style-src 'report-sample' 'self' 'unsafe-inline'; object-src 'none'; base-uri 'self'; connect-src 'self' developer.allizom.org bcd.developer.allizom.org bcd.developer.mozilla.org updates.developer.allizom.org updates.developer.mozilla.org https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://incoming.telemetry.mozilla.org https://observatory-api.mdn.allizom.net https://observatory-api.mdn.mozilla.net https://api.github.com/search/issues stats.g.doubleclick.net https://api.stripe.com; font-src 'self'; frame-src 'self' interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net mdn.github.io live-samples.mdn.mozilla.net live-samples.mdn.allizom.net *.mdnplay.dev *.mdnyalp.dev *.play.test.mdn.allizom.net https://v2.scrimba.com https://scrimba.com jsfiddle.net www.youtube-nocookie.com codepen.io survey.alchemer.com https://js.stripe.com; img-src 'self' data: *.githubusercontent.com *.googleusercontent.com *.gravatar.com mozillausercontent.com firefoxusercontent.com profile.stage.mozaws.net profile.accounts.firefox.com developer.mozilla.org mdn.dev interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net wikipedia.org upload.wikimedia.org https://mdn.github.io/shared-assets/ https://mdn.dev/ https://*.google-analytics.com https://*.googletagmanager.com www.gstatic.com; manifest-src 'self'; media-src 'self' archive.org videos.cdn.mozilla.net https://mdn.github.io/shared-assets/; child-src 'self'; worker-src 'self';
x-frame-options: DENY
origin-trial: AxVILwizhbMjxFeHOn1P3R8niO1RJY/smaK4B4d1rLzc1gTaxtXMSaTi+FoigYgCw40uFRDwFcEAeqDR+vVLOW4AAABfeyJvcmlnaW4iOiJodHRwczovL2RldmVsb3Blci5tb3ppbGxhLm9yZyIsImZlYXR1cmUiOiJQcml2YXRlQXR0cmlidXRpb25WMiIsImV4cGlyeSI6MTc0MjA3OTYwMH0=
x-cloud-trace-context: 45e10b0ad5e585fe043ca46d32af5227
date: Fri, 10 Oct 2025 19:58:38 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
String.prototype.toLowerCase() - JavaScript | MDN
Toggle sidebar
Using
String.prototype.toLowerCase()
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The toLowerCase() method of String values returns this string converted to lower case.
Try it
const sentence = "The quick brown fox jumps over the lazy dog.";
console.log(sentence.toLowerCase());
// Expected output: "the quick brown fox jumps over the lazy dog."
Syntax
js
toLowerCase()
Parameters
None.
Return value
A new string representing the calling string converted to lower case.
Description
The toLowerCase() method returns the value of the string converted to
lower case. toLowerCase() does not affect the value of the string
str itself.
Examples
Using toLowerCase()
js
console.log("ALPHABET".toLowerCase()); // 'alphabet'
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-string.prototype.tolowercase |
Browser compatibility
Loading…