Quick answer: To convert MOV, WebM or MKV to MP4, add the videos and press Convert; H.264 video is copied without re-encoding (no quality loss), other codecs are re-encoded at a high bitrate. Several files at once, downloaded as a ZIP, and nothing is uploaded.
Turn MOV, WebM and MKV files into MP4, the format every phone, TV, editor and website accepts. When the video inside is already H.264 it is copied, not re-encoded: no quality loss and done in seconds.
Convert video to MP4 at a glance
| Price | Free, no sign-up, no watermark, no daily limit |
|---|---|
| Accepts | MP4 · MOV · WebM · MKV |
| Largest file | 2 GB per file, several files at once |
| Where it runs | In your browser: files are never uploaded |
| Works on | Chrome and Edge, Safari 17+, Firefox 130+ on iPhone, Android, Windows, Mac and Linux |
| Send the result | Download it, or send it free with a link or by email (up to 20 GB) |
How to convert video to MP4
- Choose or drop one or more videos.
- Keep “Plays everywhere” for H.264 video, or choose “Fastest” to keep the video as it is.
- Press Convert to MP4. The note above the button tells you whether re-encoding is needed.
- Download the MP4s, as a ZIP if there are several, or send them with a link.
Container versus codec
A video file is a container (MP4, MOV, MKV, WebM) holding streams encoded with a codec (H.264, HEVC, VP9, AV1 for video; AAC, Opus, AC-3 for sound). Many “conversions” only need a new container: the streams are copied across unchanged. That is what this tool does whenever it can, which is why an MKV or MOV with H.264 inside converts in seconds and stays identical in quality.
| Input | Usually contains | What happens |
|---|---|---|
| MOV (iPhone, Mac) | HEVC or H.264 + AAC | H.264 copied; HEVC converted to H.264 |
| MKV | H.264 + AAC, AC-3 or Opus | Video copied; sound converted to AAC if needed |
| WebM | VP8/VP9/AV1 + Opus/Vorbis | Converted to H.264 + AAC |
Plays everywhere or fastest?
Plays everywhere makes sure the video is H.264, which plays on every device made in the last fifteen years, including older TVs and Windows PCs without extra codecs. Fastest keeps HEVC, VP9 or AV1 video as it is inside the MP4: instant and smaller, but some older devices will not play it.
Supported files and browsers
MP4, M4V, MOV, WebM, MKV and MPEG-TS files work. AVI and WMV are not supported. Converting HEVC needs a browser that can decode it (Safari, or Chrome and Edge on Windows and macOS); VP9 and AV1 decode in all current browsers. Subtitles and extra audio tracks are not carried over: the main video and sound are.
Conversion runs on your device with your browser's own video engine, so nothing is uploaded.
How this compares
| This tool | Online converters (e.g. Clideo, FreeConvert or CloudConvert) | Desktop apps (e.g. HandBrake) | |
|---|---|---|---|
| Your file is uploaded | No | Yes, to their servers | No |
| Install or account | None | Account for some features | Install needed |
| Watermark or daily limits | None | Common on free plans | Depends on the app |
Plans of other services change; check their sites. More video tools.
Frequently asked questions
Will converting to MP4 lose quality?
Not when the video is already H.264: it is copied unchanged into the MP4. Other codecs are re-encoded at a high bitrate, which keeps the quality visually the same.
Can I convert several videos at once?
Yes. Add as many as you like; they are converted one after the other and can be downloaded as a ZIP.
Can it convert AVI or WMV?
No. Browsers cannot read those older formats, so they are not offered rather than failing halfway.
Are my videos uploaded?
No. Everything happens in your browser; files are only uploaded if you choose to send the result with a link.
Need to send a big file?
Send files up to 20 GB with a download link or by email. Free, no account needed, original quality.
Send large files free