How to convert WEBM to MP4
- Drop your WEBM files into the box above, or click it to choose from your device.
- MP4 is already selected for you. Press "Convert to MP4".
- Download each new MP4 file, or grab them all at once as a ZIP.
Why convert WebM to MP4?
WebM files are best for video embedded in web pages. MP4 is the better choice for sharing and uploading video anywhere. It opens in every phone, browser, TV and editor, while WebM opens in browsers and VLC; not iPhone Photos.
MP4 uses lossy compression, so the converter encodes at high quality settings that look (or sound) identical to the original for everyday use.
WebM vs MP4 at a glance
| WebM | MP4 | |
|---|---|---|
| Compression | Lossy (VP8, VP9 or AV1) | Lossy (usually H.264) |
| Opens in | Browsers and VLC; not iPhone Photos | Every phone, browser, TV and editor |
| Best for | video embedded in web pages | sharing and uploading video anywhere |
What happens to your file
The page runs FFmpeg, the open-source media engine used inside most video and audio software, compiled to WebAssembly so it works inside your browser. Your file is converted on your own processor, which is why a long video takes longer on an older laptop, and why nothing is uploaded.
Tips for a clean conversion
- Drop a whole folder's worth of WEBM files at once. They convert one after another and you can download everything as a single ZIP.
- Keep your original WEBM files until you have checked the results. Converting back later is rarely lossless.
- MP4 is a lossy format. Convert from the best original you have, not from a file that was already compressed.
- The video engine downloads once (about 10 MB) the first time you use it, then stays cached. Long or 4K videos can take a while because the work happens on your own device.
About the formats
WebM: Open web video format used by YouTube and modern browsers.
MP4: The universal video format. Plays on virtually every phone, browser and TV.
Questions
- Is it safe to convert WEBM to MP4 here?
- Yes. The conversion runs entirely inside your web browser. Your WEBM file is never uploaded to a server, so nobody else can see it.
- Will I lose quality?
- MP4 uses lossy compression, so the converter encodes at high quality settings that look (or sound) identical to the original for everyday use.
- Can I convert several WEBM files at once?
- Yes. Drop as many files as you like. Each one is converted in turn, and you can download them one by one or all together as a ZIP.
- Is it free?
- Yes. There is no sign-up, no watermark and no limit on how many files you convert.
- Does it work on a phone?
- Yes. The converter runs in any modern browser, including Safari on iPhone and Chrome on Android, so you can convert WEBM files without installing an app.