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

Claude can write complete Datasette plugins now - 8th October 2025
Vibe engineering - 7th October 2025
OpenAI DevDay 2025 live blog - 6th October 2025

css 229 iframes 21 mobile 40 projects 499 testing 64

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