Simon Willison’s Weblog

viewport-preview (via) I built a tiny tool which lets you preview a URL in a bunch of different common browser viewport widths, using iframes.

Posted 26th July 2022 at 12 am

Recent articles

Introducing gisthost.github.io - 1st January 2026
2025: The year in LLMs - 31st December 2025
How Rob Pike got spammed with an AI slop "act of kindness" - 26th December 2025

css 230 iframes 21 mobile 40 projects 515 testing 66

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