# MP4 to WebM

Convert MP4 to WebM for smaller files on the web. Free, no signup, no watermark, and the video never leaves your device.

Canonical page: https://filetity.com/mp4-to-webm

## Capabilities

- Free: Yes, with no watermark and no page limit.
- Account required: No. There is no account system.
- Processed on device: Yes. The file is read by your browser and never uploaded. There is no server to send it to.
- Formats: MP4 in. WebM out, VP9 video and Opus audio.
- Limits: VP9 encoding is slower than H.264, so expect this to take longer than the same job in the other direction. Estimated size is shown before you start.
- Mobile: Yes, on any modern mobile browser. Large files are limited by the memory the phone gives the browser.
- Offline: Yes, once the page has loaded. The tool keeps working with no network connection.

## Questions

### Why would I want WebM instead of MP4?

For the web, mostly. VP9 typically delivers the same visible quality as H.264 in noticeably fewer bytes, which matters when the video is on a page people load on mobile data, and the format has no patent licensing attached to it. For anything going to a phone or an editor, MP4 is still the right answer.

### How much smaller will it be?

Commonly twenty to forty per cent for the same visible quality, though it depends heavily on the footage: detailed, grainy material saves less than flat animation or a screen recording. The page shows an estimate before you start and the real figure afterwards.

### Will Safari play it?

Modern Safari plays VP9 in WebM, and older versions do not. If your audience includes people on old Apple hardware, serve both and let the browser choose with a source element, which is what the format was designed for.

### Why is this slower than the other direction?

VP9 is more expensive to encode than H.264, which is the trade for the smaller output. Your device is doing that work rather than a server, so a long or high resolution video takes real minutes, and the page says so before you commit.

### Does it work for a video with no sound?

Yes. A video with no audio track converts normally and comes out with no audio track, which is what a screen recording exported without sound should do. Nothing is invented to fill the gap.

## Related tools

- [WebM to MP4](https://filetity.com/webm-to-mp4): Convert a WebM to MP4, so phones and editors will play it.
- [Compress video](https://filetity.com/compress-video): Make a video smaller without uploading it anywhere.