Compress video for iMessage

Why iMessage videos look bad

Apple's attachment ceiling is around 100MB, and in practice a 1080p clip much past five minutes starts failing. iMessage also re-compresses what you send. Sending a file that is already under the limit gives it less reason to crush the picture further, so the clip that arrives usually looks better than if you had sent the original.

How the quality is kept

File size is bitrate multiplied by duration, so hitting a smaller target means lowering one of them. Dropping resolution costs less visible quality than starving the bitrate at full resolution, so this tool scales the output down before it lets the bitrate collapse. Trimming helps even more: a 60-second clip cut to 30 seconds hits the same target at twice the bitrate.

Nothing is uploaded

The conversion runs inside your browser using WebCodecs, the same video engine the browser uses to play video. No server receives the file, so there is no account, no queue and no upload wait. You can verify it: open DevTools, switch to the Network tab, and convert a file. You will not see a request carrying it.

How to verify nothing is uploaded

1. Press F12 (or Cmd+Option+I on a Mac).
2. Open the Network tab.
3. Convert a file.
4. You will see the page assets load, and nothing carrying your video.

This is not a promise in a privacy policy. It is something you can check in ten seconds.

Questions