Video conversion
Convert MP4 to WebM
Updated Jul 2026
MP4 is the video format almost everything plays, and WebM is the format built for the web, favored by browsers for smaller, faster-loading video. To convert MP4 to WebM, open the file in a converter and export it as WebM. Doing this on your own computer means the video never has to leave your machine to get converted.
- Extension
- .mp4
- Type
- Video
- Typically
- The universal video format
- Compression
- Lossy
- Extension
- .webm
- Type
- Video
- Typically
- Web video
- Compression
- Lossy
Convert MP4 to WebM on your own computer. Nothing uploads.
How to convert MP4 to WebM
- Open Morphjet and drag in the MP4 file you want to convert, or drop in a whole folder of clips at once.
- Choose WebM as the output format.
- Convert. The WebM file is written next to your original, and nothing leaves your machine.
MP4 vs WebM: what actually changes
| MP4 | WebM | |
|---|---|---|
| Opens everywhere | Yes, plays on nearly every device, app, and player | No, plays well in browsers but not always in default media players |
| File size | Larger for the same visual quality | Smaller, built to load quickly on web pages |
| Quality | High, standard video compression | Comparable, with a small re-encoding loss on conversion |
| Editing software support | Supported by nearly all video editors | Limited, many editors need it converted before editing |
| Best use | General recording, sharing, and playback | Embedding video on websites and web apps |
| Audio | Carries over, re-encoded into WebM's audio track | Carries over, re-encoded into WebM's audio track |
When to convert, and when not to
Convert MP4 to WebM when you're embedding video on a website or web app and want smaller files that load faster in a browser.
Keep the MP4 if the video needs to play reliably in default media players, phones, or editing software, since WebM support outside browsers is inconsistent.
Why not just use an online converter?
Video files often hold personal moments, whether it's a home recording or footage you'd rather not hand over to someone else's server. Uploading an MP4 to an online converter means a stranger's server processes and, often, temporarily stores it. Converting on your own computer keeps the file, and whatever is in it, on your machine the whole time.
Questions
Does converting MP4 to WebM lose quality?
There's a small, one-time quality loss because the video gets re-encoded, similar to re-saving a JPG. At normal settings it's hard to notice, but it's not perfectly lossless.
Will a WebM file play on my phone or in Windows Media Player?
Not always. WebM plays reliably in modern web browsers, but many default media players and some phones don't open it without extra software. MP4 remains the safer choice for general playback.
Why would I convert MP4 to WebM instead of just keeping MP4?
WebM was built for the web, so it can produce noticeably smaller files at similar quality, which means faster page loads if you're embedding the video on a site.
Does the audio carry over when converting to WebM?
Yes. The audio track converts along with the video, though it gets re-encoded into the audio format WebM uses, so there can be a very small quality change there too.
Can I convert MP4 to WebM without uploading the file anywhere?
Yes. A desktop app like Morphjet converts the file locally on your computer, so it never gets sent over the internet. You could disconnect from wifi and it would still work.
Morphjet converts MP4, WebM, and 1,800+ other formats, all on your machine. Launching this July.