About Justvert
Justvert is a browser-based video converter. Files stay on your device. A Strategy Engine chooses the fastest safe path: remux when codecs already match, WebCodecs when the GPU can help, and FFmpeg WASM when compatibility matters more than speed.
Why the engine matters
Re-encoding everything with FFmpeg is simple and slow. Copying streams is almost free. Hardware encode sits in the middle. Justvert uses all three.
What Justvert is for
The homepage works as a broad online video converter. Dedicated pages cover specific jobs such as MP4 to MP3, MOV to MP4 and WebM to MP4.
About Justvert FAQ
What is Justvert?
Justvert is a browser-based video converter for common formats such as MP4, MOV, WebM and MKV. It is built to change a file from one format to another without installing software.
How does Justvert choose a conversion path?
The Media Analyzer inspects the file. The Strategy Engine then picks COPY REMUX for compatible H.264 streams, WebCodecs when the GPU can transcode, or FFmpeg WASM when a legacy container or codec needs a compatibility fallback.
Does Justvert upload my files to a server?
No. Conversion runs locally in your browser. The chosen file is read on the page, processed by remux, WebCodecs or FFmpeg WASM, then written back with a WritableStream or a download. Source files are not uploaded to a Justvert conversion server.
Is Justvert free to use?
Yes. Justvert is a free online video converter. You can convert common video and audio formats in the browser without creating an account.