How to use
- Choose a video.
- Choose the target format — MP4, MOV, WebM or MKV.
- Click the convert button and download the result.
Options explained
- Container only
- Video and audio data are copied as they are, so it is fast and lossless. If the target format cannot hold the original codec (for example H.264 in WebM), you are told to pick another format.
- Typical cases
- MOV (H.264/H.265) → MP4 and MKV (H.264) → MP4 convert directly; WebM (VP9) can go to MKV or MP4.
What each format can hold
Only the container changes, so the target must be able to hold the video codec already in the file:
| Target | Video codecs it holds |
|---|---|
| MP4 | H.264, H.265, AV1, VP9 |
| MOV | Apple QuickTime; typically H.264 or H.265 from an iPhone |
| WebM | VP8, VP9 and AV1 only |
| MKV | Almost any codec, though not every player opens it |
This is why H.264 cannot go into WebM, while VP9 from a WebM file can go to MP4 or MKV. When the codec does not fit, the tool stops with “The video codec (…) cannot be put into this format without re-encoding” and asks you to choose another format.
The result is saved with the original name and the new extension, so clip.mov converted with Convert to MP4 becomes clip.mp4.
Frequently asked questions
Why can't it convert my file?
The original codec does not fit the target format and would need re-encoding, which is slow and makes phones hot, so this tool does not do it.
Why is the file size about the same?
Nothing was recompressed — only the wrapper changed. To make a video smaller you need to compress it.
Is my video uploaded?
No. Everything happens in your browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.