Convert WEBM to MP4
Convert WEBM to MP4 free in your browser. No upload, no signup, no watermark. Files stay on your device.
drop a .webm file
or click to browse
max 500 MBrelated
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how to convert webm to mp4
Drop your WEBM file
Drag your WEBM file into the drop zone above, or click the box to pick a file from your computer or phone. The browser reads the file directly — nothing uploads.
Click Convert
The page runs ffmpeg.wasm on your device to decode the WebM and encode it as MPEG-4 Part 14. Most conversions finish in a few seconds; large or codec-heavy files (RAW, video) can take longer.
Download the MP4 file
When the conversion finishes, the MP4 file is ready to download. Save it anywhere on your device.
FAQ
common questions
Why convert WebM to MP4?
WebM is an open / royalty-free format used heavily on the web (downloads from YouTube via downloaders, Chrome screen-recording exports, modern open-source video sites), but it doesn't play universally. iOS Safari historically didn't support WebM, many smart TVs reject it, and most native video editors prefer MP4. Converting unlocks the file for those destinations.
Will I lose quality?
Some — WebM uses VP9 or AV1 codecs; MP4 typically uses H.264 or H.265. The converter has to decode the source codec and re-encode for MP4, which is a generational lossy step. At sensible quality settings the difference isn't visible in normal viewing, but it's not bit-perfect.
Will the MP4 be larger than the WebM?
Usually slightly larger. WebM's modern codecs (VP9, AV1) typically compress 15–30% better than H.264, which is MP4's standard. The MP4 trades file size for compatibility. If you specifically need a small file, sticking with WebM (where compatible) makes more sense.
What about audio?
WebM typically holds Opus or Vorbis audio; MP4 expects AAC. The converter re-encodes the audio track, which adds a small generational loss similar to the video. Speech and most music remain indistinguishable to typical listeners; critical-listening detail in complex tracks may shift slightly.
Are WebM files always smaller than MP4 originals?
Usually yes for video sourced from modern encoders (browser screen captures, YouTube downloads, modern video editors). Older or low-quality WebMs can be larger than a tightly-encoded MP4. The relevant comparison is codec efficiency at equivalent visible quality — WebM's VP9/AV1 typically wins by 15–30%, but absolute file size depends on bitrate settings, not just the format.