Online Video Converter

A local-first, workflow-friendly converter for creators and editors. Convert containers/codecs in-browser: remux when possible, transcode when needed — faster and more private with no uploads.

FAQ

Does CutFast upload my files?

No. Processing happens locally in your browser; files are not uploaded.

What’s the difference between remux and transcode?

Remux copies streams into a new container (fast and lossless). Transcoding re-encodes (slower; quality depends on settings).

Why are some codec options unavailable?

Available codecs depend on your browser’s WebCodecs encoder support and the target container’s constraints.

Which browsers are supported?

The fast path relies on WebCodecs — recommended: latest Chrome / Edge.

Will conversion reduce quality?

Remux won’t. Transcoding may; increase quality presets when needed.

Which formats are supported?

Common inputs: MP4/WebM/MOV/MKV. Outputs: MP4/WebM/MOV/MKV, plus MP3/AAC/WAV.