Convert video online
Change a video's format in your browser. When the source codecs are native to the new container (H.264/HEVC/AV1 for MP4 and MOV, VP9/VP8/AV1 for WebM), the file is simply repackaged — no re-encoding, no quality loss.
How it works
- Pick a video file — it stays on your device.
- Choose the format you need.
- Press Convert and download the result.
Limitations
Repackaging without re-encoding is possible when both tracks — video and audio — are ones the new container really plays everywhere: H.264/HEVC/AV1 with AAC/MP3 for MP4 and MOV, VP9/VP8/AV1 with Opus/Vorbis for WebM; MKV takes anything as is. Then only the wrapper changes, quality is untouched and the file is ready in seconds. Otherwise the offending track is re-encoded: a WebM with VP9 and Opus going to MP4 is re-encoded in full, and so is H.264 going to WebM. Speed depends on your device, since your browser's own codecs do the work.
Supported formats
| Format | Input | Output | Note |
|---|---|---|---|
| MP4 | Yes | Yes | H.264 / HEVC / AV1 video, AAC audio |
| WebM | Yes | Yes | VP9 / VP8 / AV1 video, Opus audio |
| MKV | Yes | Yes | Takes tracks as they are: H.264, HEVC, VP9, AV1, AAC, Opus |
| MOV | Yes | Yes | H.264 / HEVC video, AAC audio |
Frequently asked questions
Where does my file get uploaded?
Nowhere. Conversion happens in your browser, on your device — the file is never sent to a server.
Why did the conversion take less than a second?
It means the source codecs fit the new container and the file was simply repackaged — no re-encoding, no quality loss (that is what happens with MP4 → MOV or MKV, for instance). A WebM with VP9 and Opus cannot be moved into MP4 that way: MP4 players do not open such tracks, so the video is re-encoded, which takes minutes.
Which format should I choose?
MP4 — maximum compatibility: phones, TVs, editing software. WebM — smaller size for the web. MOV — for Apple devices and editing. MKV — a universal container for storage.
Does conversion lose quality?
With repackaging — none at all. If the container requires another codec and re-encoding is needed, the loss is minimal: we encode at high quality.
Can I turn MP4 into MP3?
Yes — with the Extract audio tool on this site: it pulls the audio track into MP3, M4A or WAV.
Is it free? Is there a size limit?
Free, no watermarks, no sign-up. There is no hard limit on the source, but the result is assembled in tab memory, so the browser cannot produce a file larger than 4 GB.
More tools
- Trim video online free — Cut your clip right in the browser — no sign-up, no watermarks, no quality loss. The video never uploads to a server, so even large files are fine.
- Compress video online free — Shrink your video right in the browser — no watermarks, no sign-up. The file never uploads to a server and never leaves your device.
- Extract audio from video — Save the audio track as a separate MP3, M4A or WAV file. The video never uploads to a server.
- Video to MP3 converter — free online — Convert any video to MP3 right in your browser — no sign-up, no watermarks. The file never leaves your device.
- Merge videos online — Join several clips into one, right in your browser. Nothing is uploaded to a server.
- Change video resolution online — Rescale your video to 1080p, 720p, 480p and more — right in the browser, free and without watermarks. The video never uploads to a server.
- Audio converter online — Convert audio to MP3, WAV, M4A, OGG or FLAC right in your browser — free, no sign-up. The file never uploads to a server.
- PNG to JPG converter — free online — Convert PNG to JPG, JPG to PNG or WebP right in your browser — in batches, no sign-up. Files never leave your device.
- HEIC to JPG converter — free online — Convert iPhone photos from HEIC to JPG right in your browser — in batches, no sign-up. Files never leave your device.
- Compress photos online without losing quality — Shrink photo file sizes several-fold right in your browser — in batches, with a quality slider. Files never leave your device.
- Resize images online — Shrink or enlarge pictures to exact pixel dimensions right in your browser — in batches, keeping proportions. Files never leave your device.
- Video editor — timeline editing with text and subtitles
Need more than one tool?
Kadrcut is also a full video editor in your browser: timeline, multiple tracks, text, effects and transitions. Free, no sign-up — your files never leave your device.
Try the editor