Video Converter
Turn MOV, MKV, AVI, WebM, WMV, FLV and 3GP videos into MP4, WebM, MOV, GIF, MP3 or M4A. When the codecs already fit, the video is copied in seconds with no quality loss. Free, no watermark, and your files never leave your device.
Free · No sign-upHow to use Video Converter
- 1. Drop one or more videos (MOV, MP4, MKV, WebM, AVI, WMV, FLV, 3GP, M4V…). Each file shows its codecs, size and length, plus what will happen to it.
- 2. Pick the target: MP4 (plays everywhere), WebM, MOV, GIF, or MP3 / M4A for just the sound.
- 3. Choose a quality preset and an optional max resolution (1080p, 720p, 480p). Leave ⚡ Fast copy on to skip re-encoding when the codecs already fit — for example an H.264 iPhone MOV becomes an MP4 in seconds.
- 4. Click Convert, check the verified format, codecs and length under each result, then Download — or Download all (ZIP) for a batch.
Frequently asked questions
Are my videos uploaded?
No. Conversion runs on your device with ffmpeg compiled to WebAssembly, which downloads once (about 32 MB) and is then cached by your browser. Your videos are read locally and never sent to a server.
What is Fast copy?
If the video and audio codecs are already allowed in the target container — for example H.264 + AAC in a MOV going to MP4 — the streams are copied as they are instead of being re-encoded. That takes seconds and loses no quality. If only the audio doesn't fit, the picture is copied and just the sound is converted. Uncheck Fast copy, or pick a lower resolution, to always re-encode (useful to shrink a file).
Which formats can it read?
MP4, MOV, M4V, MKV, WebM, AVI, WMV, FLV, 3GP, MPEG-TS and more, with codecs such as H.264, HEVC (H.265), VP8, VP9, MPEG-4/DivX, WMV and Flash video, and audio such as AAC, MP3, Opus, AC-3 and WMA. AV1 video can't be decoded in the browser engine: it can only be moved into MP4 with Fast copy at the original resolution.
Why is WebM output VP8 and not VP9?
The in-browser engine can't encode VP9, so re-encoded WebM files use VP8 video with Vorbis audio, which every modern browser plays. A WebM that is already VP9 or AV1 keeps its video untouched when Fast copy is on.
Is there a size or length limit?
There's no fixed limit, but everything happens in your browser's memory. Fast copy handles large files easily; re-encoding a long or 4K video can take many minutes and may run out of memory on a phone. Choosing 720p is much faster. GIF output covers the first 60 seconds — use Video to GIF to pick a part.
What's kept in the converted file?
The first video track and the first audio track, the original frame rate, rotation and basic metadata such as the title. Subtitle tracks, extra audio tracks and chapters are not carried over. HEVC videos converted to MP4 become H.264 so they play everywhere.