Convert Video
Convert between MP4, MOV, MKV, and WebM, with codec and quality control
- Files never leave your device
- Runs in your browser
- Free, no sign-up, no watermark
Drop files here, or click to choose
Accepts MP4, MOV, MKV, WebM, AVI, FLV, WMV, 3GP, MPEG · You can also paste with Ctrl+V / ⌘V
How to use Convert Video
Convert videos between MP4, MOV, MKV and WebM in your browser, several files at a time. When the new format can hold the original codecs, the streams are copied instead of re-encoded, so the conversion is instant and lossless.
- 1
Drop one or more videos on the page. MP4, MOV, MKV, WebM, AVI, FLV, WMV, 3GP and MPEG are accepted.
- 2
Under Convert to, pick MP4, WEBM, MOV or MKV, then choose a Video codec such as H.264, HEVC, AV1 or VP9.
- 3
Leave Copy streams when possible on, and set Quality and Resolution for files that have to be re-encoded.
- 4
Click Convert, then Download, or Download all (ZIP) when you converted several files.
Frequently asked questions
Are my videos uploaded to a server?
No. Conversion runs in your browser with WebCodecs, which uses your device's hardware video encoder where available. Files never leave your device.
Why is one file done instantly while another takes minutes?
If the target format can hold the same codecs, for example H.264 MP4 to MOV or MKV, the streams are only rewrapped. Otherwise the video is re-encoded, which takes about as long as your hardware needs to encode it.
What happens with AVI, WMV or other files my browser cannot decode?
They are converted with ffmpeg instead. The ffmpeg engine is downloaded once (about 32 MB) and runs much slower than the hardware path, but it still runs on your device.
Which video codec should I choose?
H.264 plays on every device. HEVC is about 40% smaller at the same quality and suits Apple devices; AV1 gives the smallest files but needs a recent device; VP9 is the usual WebM codec. Only codecs your browser can encode are offered.
Will converting reduce quality?
Copied streams are bit-for-bit identical. Re-encoding is lossy; the High quality setting keeps the most detail, Small file trades detail for size.
Can I change the resolution while converting?
You can scale down to 2160p, 1080p, 720p or 480p (by the short side, so portrait clips work too). Videos already smaller keep their size. For exact pixel sizes or social formats, use Resize Video.