Agents In Use
What’s new todayLast update
108 use cases added today

Claude Code builds a local video compression interface

Willison wanted to optimize a phone recording before publishing it. He used Claude Code for web to build a browser tool around FFmpeg compiled to WebAssembly, with multiple output presets.

Source published simonwillison.netAgent: Claudevia Claude Code
OUR ADAPTATION

Suggested prompt

Suggested prompt written by Agents In Use, not the source author. Replace bracketed inputs and review tool permissions first.

Build a local video compression page using [approved FFmpeg build]. Offer a few clearly labeled quality presets, output sizes and previews. Test with a non-sensitive sample, show the actual command for each output and report unsupported browsers. Keep processing local; do not upload the input.

Evidence at a glance

Sourced account
Source author
Simon Willison
Original account
Read the source ↗
Published
Source link checked
Reported result
The source shows a tool producing several encoded versions with previews and downloads; no general speed claim is made here.
Human involvement
Willison chose the recording and evaluated output options. Publication approval boundaries are not described.

A linked account supports attribution. It does not mean we independently reproduced its result.

Report an issue with this caseOpen correction email

Opens your email app with the case link included. Nothing is sent automatically.

How the agent did it

  1. Use the need to compress a specific phone recording as the implementation goal.
  2. Build a browser interface around the WebAssembly version of FFmpeg.
  3. Generate different encodings and compare previews and file sizes to choose a usable output.

Similar use cases

Works well with

More details

About this account

The coding agent built the tool from the delegated goal; the short account links the session but does not detail its test loop.

Firsthand tool note and screenshot document use for a real recording. Quality and timing shown are specific to that input.

Credit: Simon Willison

Source published

Added to Agents In Use

Source checked

Tools and topics

Claude Code · FFmpeg · WebAssembly

Browser · Media

Editorial completeness: 100/100. Measures documented fields, not agent performance or verified outcomes.