Blur Video

Draw boxes over faces, number plates, screens or names and blur, pixelate, cover or destroy them in your browser, without uploading the video.

Choose a video

or drop it here

The video is processed on this device and never uploaded.

MP4, MOV, WebM, MKV, AVI, WMV, FLV, 3GP, TS / MTS / M2TS or VOB / MPG

Files over 1 GB can be slow. Very large outputs need a browser that can save straight to a file.

How it works

Choose a video, then drag on the preview to draw a box over each thing you want to hide. Each box has a mode and a time range. A new box covers the whole video; Start at playhead and End at playhead narrow it to a moment. When you press Redact video, your browser decodes the video, draws the boxes into every frame and encodes a new MP4 or WebM file on your device. Nothing is uploaded.

After the conversion the page re-reads the new file, samples frames inside every box and reports whether each one is covered.

Boxes are not tracked. A box stays exactly where you drew it for its time range, so for something that moves, draw a larger box or split it into several boxes with shorter time ranges. To hide faces, Blur Faces finds and follows them automatically.

Cover fills the box with a solid colour. It is the recommended choice for text, documents, screens and number plates.
Destroy scrambles the box into a few shuffled blocks and then blurs it, so nothing in it can be recovered. Use it when the subject must never be identifiable.
Blur and Pixelate look softer but are weaker. On small areas such as text they can sometimes be reversed.

Supported files

Inputs: Any video your browser can preview: MP4, MOV, M4V and WebM almost everywhere, MKV in most desktop browsers.
Outputs: MP4 (H.264 and AAC) or WebM (VP9 and Opus), at high quality and the original resolution.

Limitations

Boxes are not tracked. Each box stays where you drew it for its time range. Blur Faces finds and follows faces automatically.
Only the picture is changed. The sound is kept, so names or details said aloud are still in the file. Use Remove Audio if the sound must go.
The video is always re-encoded, even for one small box, so it takes longer than a copy and loses a little quality.
Blur and pixelation are weaker than a solid cover and can sometimes be reversed on small areas such as text. Use Cover or Destroy for anything sensitive.
Browsers without WebCodecs use the FFmpeg fallback. It draws ellipses as rectangles with hard edges, and Destroy becomes a solid black box, which is still unrecoverable.
HDR videos are re-encoded as standard dynamic range, like every other re-encode here, so colours can look flatter.
Boxes are drawn on the preview, so a file your browser cannot play cannot be redacted here.
The output keeps the main audio track only; subtitle and other tracks are dropped. Your original file is not changed.

Questions

Which mode should I use?

Use Cover for text, screens and number plates, because a solid box leaves nothing to recover. Use Destroy when a person or object must never be identifiable but you want a blurred look rather than a box. Blur and Pixelate suit cases where a softer look matters more than certainty.

Does the box follow a moving face or car?

No. A box stays where you drew it for its time range. Draw it large enough to cover the movement, or use several boxes with shorter time ranges.

Is my video uploaded?

No. Your browser processes the video on your device, and the file never leaves it.

Can a blurred area be un-blurred?

Sometimes, for small areas with predictable content such as text. A solid cover cannot be reversed, and Destroy shuffles the pixels before it blurs them, so there is nothing left to reverse.

Is the video re-encoded?

Yes, always. The boxes are drawn into the picture, so every frame is encoded again as MP4 (H.264) or WebM (VP9) at high quality and the original resolution. The main audio track is kept; subtitle and other tracks are dropped.

Example

A 30-second dashcam clip shows a number plate from 0:04 to 0:11. Draw a box over the plate, keep the mode on Cover, set the start to 4 and the end to 11, and press Redact video. The output is the same clip with a black box over the plate for those seven seconds. The rest of the picture and the sound stay as they were.