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

Nano Banana Pro aka gemini-3-pro-image-preview is the best available image generation model - 20th November 2025
How I automate my Substack newsletter with content from my blog - 19th November 2025
Trying out Gemini 3 Pro with audio transcription and a new pelican benchmark - 18th November 2025

css 229 iframes 21 mobile 40 projects 504 testing 64

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