WebM to MP4 Converter — Free, No Upload
Convert web-native WebM files into MP4 that editors and phones accept.
Drop a file here
or click to choose a file
Runs on your device Your file is processed by your own browser and is never uploaded to a server.
Short answer
WebM files can be converted to MP4 in a browser without uploading. WebM uses the VP8 or VP9 codec, which browsers play but most video editors, phones and televisions do not. Converting re-encodes the video to H.264 and the audio to AAC inside an MP4 container, which is accepted almost universally.
At a glance
| Accepts | WebM (VP8 / VP9) |
|---|---|
| Produces | MP4 (H.264 / AAC, faststart) |
| Processing | In your browser |
| Price | Free, no limits |
| Account | Not required |
WebM is common because screen recorders, browser-based capture tools and many web downloads produce it by default. It is an excellent web format and a frustrating one everywhere else — dropping a WebM into a video editor or sending one to a phone often just fails.
Converting to MP4 with H.264 solves that at the cost of one re-encode. File size typically grows slightly, since VP9 is a more efficient codec than H.264, but compatibility improves dramatically.
How to use it
- 1
Add the WebM file
Drop in the .webm file you want to convert.
- 2
Choose quality
Balanced suits most files; High keeps more detail.
- 3
Convert
Video is re-encoded to H.264 and audio to AAC, locally.
- 4
Download the MP4
Save the result.
Frequently asked questions
Why will my WebM not open in a video editor?
Most editors do not include VP8 or VP9 decoders. Converting to MP4 with H.264 makes the file readable by essentially every editor.
Will the MP4 be larger than the WebM?
Often slightly, because VP9 compresses more efficiently than H.264 at the same visual quality. Lower the quality setting if size matters more than fidelity.
Does the conversion lose quality?
Yes, a small amount, as with any re-encode between lossy codecs. It is not noticeable at the Balanced or High setting.
Can I convert MP4 back to WebM?
Yes, use the Video to WebM tool for the reverse direction.