Video Converter
Whether a video plays comes down to two things: the container – MP4, MOV, MKV or WebM – and the codecs for picture and sound inside it. Here you'll find every video converter on wandlio: into MP4 and back, audio as MP3 or WAV, short clips as GIF, and subtitles between SRT and WebVTT.
Your browser handles all of these jobs itself, with no upload – mostly with its built-in codecs, otherwise with ffmpeg.wasm.
All video converters
“Browser” means the conversion runs in your browser with no upload – your file stays on your device. “Server” means the file is sent over an encrypted connection (HTTPS) to our servers in Germany and deleted right after conversion.
Convert to MP4
MP4 is broadly supported. If the tracks already fit (H.264 video, AAC audio), wandlio just repackages them; other codecs such as HEVC are re-encoded by your browser's built-in codecs – H.264 for the picture, AAC for the sound.
- Convert MOV to MP4 Browser
- Convert MKV to MP4 Browser
- Convert WebM to MP4 Browser
- Convert AVI to MP4 Browser
Other containers
MP4 and MOV become WebM for websites, encoded by your browser with the open codecs VP9 and Opus; MP4 can also become MOV for Apple software or AVI for older programs.
- Convert MP4 to WebM Browser
- Convert MOV to WebM Browser
- Convert MP4 to MOV Browser
- Convert MP4 to AVI Browser
Audio from video
Keeps only the soundtrack of a video, say a talk or an interview – as MP3 for listening or WAV for editing. MP4 to MP3 also accepts MOV, WebM, MKV and AVI files.
- Convert MP4 to MP3 Browser
- Convert MP4 to WAV Browser
Video to GIF
MP4 and WebM clips become an animated GIF at 12 frames per second and 480 pixels wide. Short excerpts of a few seconds work best.
- Convert MP4 to GIF Browser
- Convert WebM to GIF Browser
Subtitles
SRT and WebVTT both store timestamps and text. WebVTT is the format intended for videos on web pages that use the HTML track element. Converting is plain text processing in your browser.
- Convert SRT to VTT Browser
- Convert VTT to SRT Browser
Container vs. codec: what fits where?
The container is the packaging; the codec is the actual compression of picture and sound.
| If you want to … | Use … | Good to know |
|---|---|---|
| play a video on as many devices as possible | MP4 with H.264 and AAC | the usual combination when compatibility comes first |
| embed a video on a web page | MP4 or WebM | WebM uses open codecs: VP8, VP9 or AV1 for video, Vorbis or Opus for audio |
| keep several audio or subtitle tracks in one file | MKV | extra tracks may be lost when switching to MP4 |
| show a short clip without a video player | GIF | 256 colours at most and no sound |
| keep only the sound | MP3 or WAV | MP3 is small, WAV is lossless |
| add subtitles to a web video | WebVTT (.vtt) | every file starts with the line WEBVTT |
Video formats explained
- MP4
- A container from the MPEG-4 standard. It can hold H.264, AV1 or VP9 video and AAC, MP3 or Opus audio, among others.
- MOV
- Apple's QuickTime format. MDN notes it is mainly at home on Apple devices; among browsers, only Safari plays it reliably.
- MKV
- Matroska is an open container that can carry many video, audio and subtitle tracks in a single file.
- WebM
- Built on Matroska and designed for the web: VP8, VP9 or AV1 for video, Vorbis or Opus for audio.
- H.264 and AAC
- The two codecs used when re-encoding to MP4 or MOV: H.264 for the picture, AAC for the sound. Your browser's built-in codecs do this; AVI gets H.264 with MP3 audio.
- SRT and WebVTT
- SRT separates the milliseconds in a timestamp with a comma (00:00:01,000), WebVTT with a full stop; a WebVTT file also begins with the line WEBVTT.
Limits of in-browser conversion
Most conversions run on your browser's built-in codecs, often with help from the graphics chip. What they can't read, such as AVI files, is read first by ffmpeg.wasm on a single CPU core; benchmarks in the ffmpeg.wasm documentation show this is far slower than FFmpeg as an installed program, so allow extra time for long videos.
For ffmpeg.wasm, the same documentation lists 2 GB as a hard limit of WebAssembly; with the browser's codecs, the finished video has to fit in memory. For very large files, a desktop program is the better choice.
In our test, Firefox couldn't read HEVC or create AAC. When a video has to be re-encoded for MP4 or MOV, Chrome or Edge is the safe choice.
With every video converter, your file stays on your device.
Video guides
More on codecs, containers and in-browser conversion:
Related categories
- Convert audio
Convert audio files between MP3, WAV, FLAC, OGG and M4A.
- Convert images
Move stills and GIFs to other image formats.