Convert Video
Convert Video changes a clip from one format to another — MP4, WebM, MOV or MKV — so it plays on the device, editor or platform you need. MP4 with H.264 is the safe choice almost everywhere, while WebM is smaller and web-native. The whole conversion runs in your browser with FFmpeg.wasm, so your file is never uploaded.
Add your video
The file is read by your browser and stays on your device — there is no upload step.
How to use Convert Video
- 01Upload
Add your video
Drag an MP4, MOV, WEBM, MKV or AVI file onto the page, or click to browse. It loads straight in — no upload.
- 02Customize
Pick a target format
Choose MP4, WebM, MOV or MKV. The tool defaults to a format different from your source.
- 03Process
Convert & download
Export to re-encode the clip into the new format, then download it.
Is converting the right move?
- The device or editor will not open itConvert Video
- It plays, but the file is too largeCompress Video
- It is higher resolution than neededResize Video
- You only need it as a short loopVideo to GIF
What changes in the conversion
- A generation of quality
Converting between compressed formats decodes and re-encodes the picture. Each pass costs a little detail, and it never comes back.
- Subtitle and chapter tracks
MKV can carry several subtitle tracks and chapters; MP4 support is narrower. Extra tracks are commonly dropped.
- Time
Video conversion is the slowest operation on this site. A long clip re-encodes in real time or slower, in your own browser.
Container and codec, which are not the same thing
| Format | Best for | Avoid when |
|---|---|---|
| MP4 (H.264) | Anything that has to just work — phones, browsers, editors, TVs | You need the very smallest file and control the playback end |
| WebM (VP9) | Web embedding; smaller than H.264 at similar quality | It must open in older desktop software |
| MOV | Handing footage to Apple editing software | Sending to someone on Windows without checking |
| MKV | Archiving with multiple audio and subtitle tracks | Uploading — many platforms reject the container outright |
Supported formats
- MP4
- MOV
- WebM
- AVI
- MKV
- Maximum file size —
- bounded by your device's memory
- Processed by —
- FFmpeg (WebAssembly), on your device
Your file, and what the page does
Your file is never uploaded. Convert Video reads it into this browser tab and processes it with FFmpeg compiled to WebAssembly on your own device. There is no upload endpoint in the application and no copy on any server — closing the tab discards it.
That is also why processing takes longer here than on a site that uploads: your device is doing the work rather than a rack of servers. The trade is that the file never leaves it.
What the page does send or fetch
- The processing engine, once
- The first time you use any video or audio tool, the browser downloads the FFmpeg WebAssembly build (~30MB) from the jsDelivr CDN and reuses the cached copy afterwards. That is a file coming to you — no part of your own file is in the request.
- Ads on the page
- The site is funded by advertising, so the page loads Google AdSense. That carries the usual web basics — IP address, browser, referring page — as on any ad-supported site.
- An anonymous usage counter
- When Convert Video finishes we record that the tool ran, whether it succeeded and how long it took. No file data, no identifier, no cookie.
Your file is not on that list. How this works.
Frequently asked questions
MP4 (H.264) plays on virtually every device and app. Pick WebM for smaller, web-optimised files, or MOV/MKV when a specific tool requires them.
The clip is re-encoded once at a high-quality setting, so any change is minimal. Converting to WebM uses VP9; the others use H.264.
For GIFs, use the dedicated Video to GIF tool — it builds a colour palette for clean, band-free animation.
Yes — Convert Video is completely free. There's no account, sign-up, watermark or limit.
No. It runs in any modern browser — Chrome, Edge, Safari, Firefox, Brave — with nothing to download or install.
Not sure converting is what you need?
- Will not play where you need itConvert Video
- Plays fine, too largeCompress Video
- Wrong resolutionResize Video
- Only the audio is wantedExtract Audio
Edit any media with a right-click
Add Dexta Studio to Chrome and open any image, video, audio or PDF straight into the right tool — free, nothing uploaded.