How to convert a video
- Choose a file. Select or drop a MOV, WebM, MKV or AVI video. MP4 files can be remuxed too. The input limit is 2 GB, though your browser may have a lower practical memory limit.
- Wait for local processing. The first conversion downloads the video engine. Compatible streams are copied into MP4; incompatible codecs produce an error.
- Download the result. Save the new MP4 after processing completes. Test it in your target player before deleting your original file.
Files this page accepts
| Input | Extension | Typical source |
|---|---|---|
| QuickTime | .mov | iPhone or Mac video |
| WebM | .webm | Browser recording |
| Matroska | .mkv | OBS or desktop video |
| AVI | .avi | Older camera or Windows software |
| MP4 | .mp4 | Repackage a compatible MP4 |
What changes in the output?
MP4 is a container. This tool copies compatible video and audio streams into an MP4 file without re-encoding, preserving their quality. A file extension alone does not guarantee that its codecs fit MP4. Many WebM files use VP8 or VP9 video with Opus audio and cannot be remuxed here; the tool shows an error for those files. Keep the original file.
Privacy and limits
The selected file is processed by WebAssembly inside your browser. It is not uploaded to our servers. The conversion engine itself must be fetched on first use, so you need a connection at least for that step. Video processing consumes device memory and CPU; files near the 2 GB technical limit may fail on systems with less free memory. Keep your original until you have played the converted file and confirmed that picture and sound are present.
Frequently asked questions
- Does my video get uploaded?
- No. Video processing runs in your browser. The conversion engine is downloaded when you choose a file, but the file itself is not sent to our server.
- Which files can I convert?
- You can select MOV, WebM, MKV, AVI or MP4 files. Only audio and video codecs compatible with MP4 can be copied; many WebM files cannot be converted by this tool.
- Will the quality change?
- A successful conversion copies the audio and video streams without re-encoding, so their quality does not change. Incompatible codecs produce an error instead of being re-encoded.
- What is the file size limit?
- The hard input limit is 2 GB. Large files can still exceed the memory available on your device or browser, so start with smaller files.
- Does it work on a phone?
- It may work for smaller files on a recent phone. The video engine uses significant memory; a desktop browser is more reliable for larger files.
Related tools
Need a file from a public video link instead? Use the video downloader or the YouTube to MP4 guide.