Convert video to MP4, WebM, MOV, MKV, AVI or GIF
Convert videos to MP4, WebM, MOV, MKV, AVI or GIF, copying streams losslessly when the format allows.
A video file is a container (MP4, MOV, MKV, WebM, AVI) holding streams encoded with codecs (H.264, HEVC, VP9, AAC, Opus and so on). Whether a file plays depends on both. An MKV from a camera, a WebM screen recording or an old AVI might refuse to open in your editor, phone or upload form even though the picture inside is perfectly fine. This converter moves video between the six common formats with the codecs each one is known for.
When the streams inside are already allowed in the target container, Auto mode copies them without re-encoding: an H.264 MKV becomes an MP4 in seconds with no quality loss, and a VP9 WebM becomes an MKV the same way. When they are not (HEVC into MP4, anything into WebM or AVI), the video is re-encoded: H.264 with AAC audio for MP4, MOV and MKV; VP8 with Opus for WebM (VP9 files are copied as they are, but the in-browser VP9 encoder is not reliable enough to offer); MPEG-4 Part 2 (Xvid-compatible) with MP3 for AVI. GIF output takes the first 30 seconds at the frame rate and width you pick, with a palette optimised for the clip. The result card says which path was used.
Everything runs in your browser with FFmpeg compiled to WebAssembly. The engine is about 32 MB and downloads once. Re-encoding is single-threaded, so expect roughly real time for 720p on a laptop and slower for 1080p; stream copies are fast at any size. Files up to 500 MB are accepted.
How to use it
- Drop a video: MP4, MOV, M4V, WebM, MKV, AVI or 3GP.
- Choose the output format. Leave Conversion on Auto to copy streams whenever the format allows.
- Pick a quality for re-encoding (or the frame rate and width for GIF).
- Click Convert, wait for the progress bar and download the new file.
Frequently asked questions
Which format should I pick?
MP4 for almost everything: phones, Windows, Mac, social media and websites. WebM for web pages that want an open format, MOV for Apple editing apps, MKV to keep unusual codecs or several tracks, AVI only for old players and TVs, GIF for short silent loops.
Will I lose quality?
Not when the streams are copied (the note says so). Re-encoding is lossy; Balanced quality looks very close to the source, High is closer still at a larger size.
Why does WebM output use VP8 rather than VP9?
VP9 makes smaller files, but its encoder crashes in the single-threaded WebAssembly build of FFmpeg this page uses, so WebM is encoded with VP8 and Opus, which every browser plays. A WebM that already contains VP9 is copied without re-encoding.
Are subtitles and extra audio tracks kept?
The first video and first audio stream are converted; subtitle tracks and additional audio languages are left out.
Why only 30 seconds for GIF?
GIF stores every frame as a palette image, so files grow very quickly. For a specific range with more options, use Video to GIF.
Related tools
- Convert MOV to MP4Convert iPhone and Mac MOV videos to MP4 that plays on Windows, Android and the web.
- Compress a video to a target file sizeCompress MP4, MOV or WebM to a target size in MB without uploading it.
- Resize a videoChange a video to 1080p, 720p, 480p or a social size (square, 4:5, 9:16) with bars or crop-to-fill.
- Crop a videoCrop a video with a drag-and-drop box and presets for 1:1, 9:16, 16:9 and 4:5.
- Convert a video to GIFTurn a clip of an MP4, MOV or WebM into a looping GIF with an optimised colour palette.
- Extract MP3 audio from a videoExtract the audio track of an MP4, MOV or WebM as an MP3, entirely on your device.