How to compress video and convert to MP4

Choose one MP4, MOV or WebM up to 100 MB and 180 seconds. Select 16 MB or 64 MB and Create MP4. Download after the output size has been checked.

Quality and compatibility

Output uses H.264, AAC and yuv420p, at most 1280 px wide and 30 fps. Video may be downscaled; HDR and multichannel audio may change. A supported container does not imply support for every codec it can contain.

Reproducible example

A 30-second 640 × 360 WebM with audio can be converted to MP4. The 16 MB target means fewer than 16,000,000 bytes. The app checks the real size before offering a download.

Download the test WebM (2.70 MB) · View the MP4 output (2.39 MB). The synthetic sample contains colour patterns and a tone, no personal data; tested in desktop Chromium on 23 October 2026.

If processing fails

Close other tabs, try a smaller video or use a computer with more memory. Empty, damaged, overlong or unsupported videos are rejected. Cancel stops processing without changing the original.

The engine downloads about 32 MB on first use. Your video stays in the browser. Processing time depends on your device and the video complexity.

Corresponding source and engine licence · ffmpeg.wasm documentation