Can it follow a moving face?

Not yet. Areas stay where you draw them; cover the path the face takes, or split the clip and blur each part.

Are my files uploaded?

No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.

Is it free? Are there limits or watermarks?

Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.

Does it work offline?

Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

Home / Video / Blur Part of a Video

Blur Part of a Video

Blur, pixelate or black out faces, plates and screens in fixed areas, for the whole video or a time range.

Free, no uploads, no sign-up. Runs 100% in your browser.

How Blur Part of a Video works

Video work runs in ffmpeg.wasm, the FFmpeg toolkit compiled to WebAssembly (GPL build, loaded as a separate engine file of about 30 MB the first time, then cached).

Input: MP4, MOV, WEBM, MKV, AVI. Output: MP4.

How to use Blur Part of a Video

Drop a video onto Blur Part of a Video.
The first run downloads the ffmpeg engine (about 30 MB, once).
Set your range, format or quality options.
Process it (progress is shown live), then download.

Tips

Shorter clips and lower resolutions process much faster.
Processing speed depends on your CPU; plug in laptops for long jobs.
Keep the tab in the foreground while encoding.

Blur Part of a Video FAQ

Can it follow a moving face?: Not yet. Areas stay where you draw them; cover the path the face takes, or split the clip and blur each part.
Are my files uploaded?: No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.
Is it free? Are there limits or watermarks?: Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.
Does it work offline?: Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

Related tools

Remove Logo from Video: Fill in a fixed logo, watermark or date stamp from the surrounding pixels.
Blur & Redact Image: Auto-detect faces or paint areas to blur or pixelate.
Crop Video: Crop a video visually with aspect presets for Reels, Shorts and TikTok (9:16), square (1:1) and portrait (4:5).
Video Trimmer: Trim and cut clips with a visual timeline, no re-upload.