Simon Willison’s Weblog

25th January 2009 - Link Blog

OCR and Neural Nets in JavaScript. John dissects the brilliant Greasemonkey script that solves simple captchas using the canvas element and HTML5’s getImageData API.

Posted 25th January 2009 at 12 am

Recent articles

Generating running routes with GPT-6 Astra and ChatGPT Work - 12th September 2026
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Some thoughts on the Navier–Stokes Millennium Prize Problem - 8th September 2026

This is a link post by Simon Willison, posted on 25th January 2009.

canvas 38 captchas 9 getimagedata 1 greasemonkey 54 javascript 764 john-resig 33 ocr 26

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