Simon Willison’s Weblog

What is a Polyfill? Useful new term: a Polyfill is “a shim that mimics a future API providing fallback functionality to older browsers”.

Posted 9th October 2010 at 11:48 am

Recent articles

A new way to extract detailed transcripts from Claude Code - 25th December 2025
Cooking with Claude - 23rd December 2025
Your job is to deliver code you have proven to work - 18th December 2025

browsers 93 recovered 213 polyfill 2 remy-sharp 3

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