Simon Willison’s Weblog

JavaScript/CSS Font Detector (via) Really clever trick: detects the fonts that you have installed by writing out some text and measuring its dimensions.

Posted 20th March 2007 at 11:20 pm

Recent articles

My Lethal Trifecta talk at the Bay Area AI Security Meetup - 9th August 2025
The surprise deprecation of GPT-4o for ChatGPT consumers - 8th August 2025
GPT-5: Key characteristics, pricing and model card - 7th August 2025

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