Convert Video to MP4
Turn MOV, WebM, MKV and other videos into MP4 that plays on any phone, computer or editor. Everything runs in your browser; the video is never uploaded.
Your file never leaves your device. How?
Your media is processed in your browser and is not uploaded to our servers for conversion. Page assets (including the converter engine) still load over the network.
Select or drop a video to convert to MP4
MOV, WebM, MKV, AVI, M4V and more. Converted on your device.
Click, tap, or drop a fileHow to convert a video to MP4
Choose the video
Drop or select a MOV, WebM, MKV, AVI or other video file.
Pick a mode
Fast keeps the original quality and takes seconds. Maximum compatibility re-encodes to H.264 so it plays everywhere.
Convert
Conversion runs on your device. You can cancel at any time.
Check and download
Play the MP4 in the page to confirm it works, then download it.
How the conversion works
A video file is a container (MOV, WebM, MKV, MP4) holding compressed video and audio streams. Fast mode moves the existing streams into an MP4 container without touching them, which is quick and lossless.
That only helps if the streams inside are ones players understand in MP4, typically H.264 or HEVC video with AAC audio. WebM files and some iPhone videos need Maximum compatibility, which decodes the video and re-encodes it as H.264 with AAC audio using FFmpeg in WebAssembly.
Features
Lossless Fast mode
Rewraps the video without re-encoding, so quality is identical and large files finish in seconds.
Plays everywhere
Maximum compatibility produces H.264 and AAC in MP4, the most widely supported combination.
Streaming-friendly
The MP4 index is placed at the start of the file so it starts playing immediately when shared or uploaded.
Private
Nothing is uploaded, so personal and work videos stay on your device.
Frequently asked questions
Is my video uploaded?
No. The conversion runs in your browser with a WebAssembly build of FFmpeg. The video is read from your device and the MP4 is saved back to it.
What is the difference between Fast and Maximum compatibility?
Fast copies the existing video and audio into an MP4 without re-encoding, so it takes seconds, keeps the exact quality and handles files up to 500 MB on a computer. Maximum compatibility re-encodes to H.264 and AAC, which play everywhere, but it is slower and works for videos up to 120 MB and 10 minutes on a computer.
How large a video can I convert?
Fast mode handles up to 500 MB on a computer and 250 MB on a phone. Maximum compatibility re-encodes every frame in the browser, so it is limited to 120 MB and 10 minutes on a computer, or 60 MB and 5 minutes on a phone. Trim longer videos first.
Which formats can I convert?
MOV, WebM, MKV, M4V, AVI, 3GP, FLV and MPEG-TS files usually work. Support depends on the codecs inside; if a file fails in Fast mode, try Maximum compatibility.
Why is my converted video still not playing?
In Fast mode the original codecs are kept. If they are VP9, Opus or HEVC, some players still can't open the MP4. Convert again with Maximum compatibility.
Are multiple audio tracks or subtitles kept?
The first video track and the first audio track are kept. Subtitle and extra audio tracks are left out because MP4 players handle them inconsistently.
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