Blur or pixelate part of a video, right in your browser
A number plate in a dash-cam clip, a laptop screen with private messages, an address on a parcel, a child’s school badge, a brand you are not allowed to show — this free blur video tool hides any part of a video. Draw a rectangle over it on the preview, choose blur, pixelate or a black box, and set how strong the effect should be.
Every area has its own time range, so a plate can be hidden only while it is on screen and a screen only during the seconds it shows something private. You can also blur or pixelate the whole frame, for the entire video or just between two timestamps. The video is decoded, edited and encoded on your device with Mediabunny and your browser’s WebCodecs — nothing is uploaded.
How to use the Blur Video
- Drop the video on the upload area. Duration, resolution, frame rate, codecs and file size appear under the preview.
- Choose the effect — Blur, Pixelate or Black box — and the strength. To hide everything, switch “Apply to” to Whole frame.
- Drag on the preview to draw an area. Move it by dragging, resize it with its round handle, and add as many areas as you need.
- In the list under the preview, untick “Whole video” for an area and enter when it starts and ends, or scrub to the right frame and press “Now”.
- Press Blur video, check the result with the Before/After buttons and press Download video.
Blur Video features
Blur, pixelate or black box
A smooth Gaussian-style blur, chunky averaged pixel blocks, or a solid box that leaves nothing of the original.
Areas with time ranges
Each rectangle can cover the whole video or only a chosen span, accurate to the frame, so the rest of the clip stays sharp.
Whole-frame mode
Blur or pixelate the entire picture — for example to hide a spoiler at the end or to create a soft background clip.
Touch-friendly drawing
Draw, move and resize areas with a finger, pen or mouse; drawing on the preview does not scroll the page.
Audio unchanged
Only the picture is re-encoded; the soundtrack is copied as it is whenever the output format can hold it.
No upload
All processing happens on your device. There is no account, no file size limit set by a server and no watermark.
How the blur is applied
Mediabunny (open source, MPL-2.0) reads your file and hands each decoded frame to the page. The frame is drawn on a canvas at full resolution, the chosen areas are blurred with the browser’s canvas blur filter or pixelated by averaging blocks of pixels, and the frame goes to the browser’s built-in encoder — H.264 for MP4 and MOV, VP9 for WebM — with its original timestamp. Strength is measured relative to the video’s size, so the preview looks the same as the saved file.
Areas stay where you draw them; they do not follow moving objects. For something that moves, draw a larger area that covers its whole path, or split the time into several areas, each placed for its own few seconds. For faces that move around, Face Blur Video detects and follows them automatically.
Which effect should I use?
| Effect | Good for | Keep in mind |
|---|---|---|
| Blur | Natural-looking privacy for faces, backgrounds and screens | Light blur can leave large text readable — use a high strength |
| Pixelate | A clear “censored” look for plates and documents | Bigger blocks hide more; strength sets the block size |
| Black box | Passwords, card numbers, ID documents | Nothing of the original survives, so it cannot be reversed |
Privacy tips and limits
- Scrub through the whole result: a plate or face that enters the frame early or leaves late may need a longer time range.
- Pixelated or lightly blurred text can sometimes be guessed; for anything sensitive use Black box.
- Very long or very large videos are kept in memory until you download them; shorten them first with Trim Video if your device struggles.
- For a single photo or screenshot, Pixelate Image does the same job instantly.
- The tool needs WebCodecs: current Chrome, Edge and Opera, Firefox 130 or later on a computer, or Safari 16.4 or later.
Blur Video FAQ
How do I blur part of a video for free?
Open the video here, drag a rectangle over the part you want to hide, choose Blur and a strength, and press “Blur video”. Download the result when it is ready — no sign-up and no upload.
Can I blur something for only a few seconds?
Yes. In the list under the preview, untick “Whole video” for that area and enter its start and end times, or scrub to the moment and press “Now”.
Does the blur follow a moving object?
No. Areas stay where you draw them. Cover the whole path of the object, or use several areas with different time ranges. Moving faces are tracked automatically by Face Blur Video.
How do I pixelate a whole video?
Choose Pixelate, switch “Apply to” to “Whole frame” and press “Blur video”. Use “From – to” to pixelate only part of the video.
Can a video blur be undone?
Not from the saved file: the original pixels are replaced. Light blur and small pixel blocks may still let people guess large shapes or text, so use a high strength or a black box for sensitive details.
Is my video uploaded?
No. The video is processed entirely inside your browser and never leaves your device.