Convert video

Convert video features

• 01

  All major formats supported

  Convert between MP4, WebM, MOV, and MKV. MP4 works everywhere, WebM is optimized for the web, MOV is native to Apple devices, and MKV is the go-to container for high-quality archiving.

• 02

  Quality control with CRF slider

  A quality slider (1–100) lets you fine-tune the balance between file size and visual quality. Higher values preserve more detail; lower values produce smaller files.

• 03

  100% private — nothing is uploaded

  All conversion is powered by FFmpeg compiled to WebAssembly and runs entirely on your device. No account, no upload, no data ever leaving your machine.

Convert video FAQ

How do I convert a video to a different format?

Drop your video onto the upload area (or click Choose file), select the output format from the ‘To’ selector, adjust the quality slider if needed, then click Convert. Download the result when it’s ready.

What is the difference between MP4, WebM, MOV, and MKV?

MP4 (H.264) is the most universally compatible format, supported on virtually every device and platform. WebM (VP9) is optimized for web delivery with smaller file sizes. MOV is Apple’s native container, ideal for macOS and iOS workflows. MKV is a flexible open container popular for high-quality video archiving.

Will the video quality change after conversion?

Yes — converting between formats requires re-encoding, which involves some quality trade-off. Use the quality slider (75 or above) to preserve visual fidelity. The output will not be identical to the source, but at high quality settings the difference is barely perceptible.

Is there a file size limit?

The maximum supported file size is 1 GB. Conversion happens locally in your browser, so very large files may be slow depending on your device’s CPU speed.

Are my videos uploaded to a server?

No. The converter runs entirely inside your browser using FFmpeg WebAssembly. Your video files never leave your device and nothing is stored or logged.