CARVIEW |
Fuzzy max-age Calculator
Cache-Control
’s
max-age
directive accepts a duration in seconds, but seconds aren’t particularly
human-friendly. This calculator allows you to specify max-age
in much more
palatable terms and end up with a compliant max-age
format. Alternatively, you
can paste an existing max-age
value and get its human-friendly equivalent.
Give it a go!
Cache-Control:
- Human-friendly version:
Disclaimer: This max-age
calculator aims to provide
convenient and human-friendly conversions between time periods and cache
durations. While I strive for accuracy, there may be edge cases or unexpected
behavior in certain input formats. As this tool interprets natural language and
various time units, I encourage users to verify important calculations and be
mindful of potential inaccuracies in highly complex inputs. I welcome feedback
and suggestions! If you encounter any issues, or if you’d like to contribute
improvements, please feel free to submit them to the GitHub repo at
github.com/csswizardry/csswizardry.github.com.
Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.
Connect
Projects
- ITCSS – coming soon…
Next Appearance
-
Talk
JoyConf: Amsterdam (Netherlands), October 2025
Learn:
- Understand
Cache-Control
- Core Web Vitals and SEO
- CSS Performance
- Does
DOMContentLoaded
Still Matter? - Push Speculation Rules to the Max
- Improve Web Performance on iOS
max-age
calculator- Core Web Vitals on iOS
- Design for High Latency
- Optimise Largest Contentful Paint
- Speed Up Google Fonts
- Can We Drop Our Build Tools Yet?
- Get the Fastest Possible LCP
- Diagnose Time to First Byte
- What Is the Maximum
max-age
Value?
I help teams achieve class-leading web performance, providing consultancy, guidance, and hands-on expertise.
I specialise in tackling complex, large-scale projects where speed, scalability, and reliability are critical to success.