Which video formats can I convert between?

You can convert MP4, MOV, WebM, AVI, and MKV inputs into MP4 (H.264), WebM (VP8), MOV, or AVI. MP4 is the most widely compatible choice for phones, browsers, and social media.

Why is conversion slow for big files?

Everything runs locally in your browser using FFmpeg compiled to WebAssembly, which is single-threaded. For a smooth experience keep clips under about 100MB — larger or longer videos can take several minutes.

Is my video uploaded to a server?

No. All processing happens on your device using WebAssembly. Your video never leaves your browser, so it stays completely private.

Why is MOV to MP4 almost instant sometimes?

When the source already uses compatible codecs (H.264 video and AAC audio), we simply repackage the file into the new container without re-encoding. If the codecs are incompatible, we automatically fall back to a full re-encode.

What is the difference between MP4 and WebM?

MP4 (H.264 + AAC) plays virtually everywhere. WebM (VP8) is an open, royalty-free format optimized for the web. Choose MP4 for maximum compatibility and WebM when you specifically need an open format.

Video Converter

Convert videos between MP4, WebM, MOV, and AVI right in your browser. Fast, free, and private — nothing is uploaded.

Drag & drop your video file here

Supported: MP4, MOV, WebM, AVI, MKV

Runs entirely in your browser — for best speed keep clips under ~100MB.

How to Convert a Video

Change your video's format in 3 simple steps.

Upload your video

Drag and drop or select an MP4, MOV, WebM, AVI, or MKV file.

Choose a format

Pick MP4, WebM, MOV, or AVI as your output format.

Convert & download

Run the conversion, preview the result, and download instantly.

Conversion Tips

Get the best results from your conversions.

MP4 for Compatibility

MP4 (H.264 + AAC) plays on virtually every device, browser, and social platform — a safe default.

Instant Remux

MOV → MP4 (and similar) can be near-instant because we repackage without re-encoding when the codecs already match.

Keep Clips Small

Because everything runs locally in WebAssembly, clips under ~100MB convert fastest and most reliably.

WebM is Open

Choose WebM (VP8) when you specifically need a royalty-free, web-optimized format. Encoding is slower than MP4.