About this tool
A video converter changes a local video into MP4 with H.264 and AAC, WebM with VP8 and Opus, MOV, MKV, AVI, or an animated GIF. It is useful when a player, editor, website, or messaging service needs a different container or codec combination than the source file provides.
Conversion runs in your browser with FFmpeg compiled to WebAssembly, so the video is never uploaded and nothing is kept after the tab closes. The roughly 32 MB engine downloads from a CDN on first use and is then cached. Processing uses one CPU thread, depends on your device, and can be canceled at any time.
How to use the Video Converter
- 1Choose the local video file that needs a different format.
- 2Select MP4, WebM, MOV, MKV, AVI, or animated GIF output.
- 3Start conversion after the FFmpeg engine finishes its first download.
- 4Watch progress and cancel the job if you need to stop.
- 5Download the converted video after browser processing completes.
Features
Six video outputs
Create MP4, WebM, MOV, MKV, AVI, or animated GIF from supported input.
Specified web codecs
Use H.264 with AAC for MP4 or VP8 with Opus for WebM.
Browser FFmpeg engine
Run media conversion through FFmpeg compiled to WebAssembly on your own device.
Cached engine download
Download about 32 MB once from a CDN, then reuse the browser cache.
Cancelable conversion jobs
Stop an active encode without waiting for the entire file to finish.
Frequently asked questions
Which formats can the video converter create?
Output choices are MP4, WebM, MOV, MKV, AVI, and animated GIF. MP4 uses H.264 and AAC, while WebM uses VP8 and Opus.
Why is there a download before my first conversion?
The page needs the roughly 32 MB FFmpeg WebAssembly engine. Your browser normally caches it after the first CDN download.
Why does a long or high-resolution video take time?
Encoding speed depends on your device and uses one CPU thread. Longer and higher-resolution files require more processing.
What video file sizes can the browser handle?
Files above about 500 MB may be slow or run out of memory. The hard file limit is 2 GB.
Is my source video uploaded for conversion?
No. FFmpeg processes it locally in the browser, and you can cancel the job whenever needed.