Blur Video — Blur, Pixelate or Hide Part of a Video

Before you share a video you may need to hide something: a face, a licence plate, a screen with private details, a name badge or a channel logo. This tool blurs, pixelates or blacks out the areas you mark, for the whole clip or only between two times, or fills a small logo or watermark from the pixels around it. Mark the area in percent of the picture and check the preview frame, then process the video. It runs entirely in your browser, so the footage you want to protect never leaves your device.

How to use this tool

1. Choose the video and the effect.
2. Enter the area as left, top, width and height in percent of the picture (add more areas below, one per line); the preview frame shows it with a yellow outline.
3. Optionally limit the effect to a time range, and pick the strength.
4. Untick "Preview only" and run it again to process the whole video, then download the MP4.

Formula

Area in pixels: x = left% × width ÷ 100, y = top% × height ÷ 100 (rounded to even numbers)

Percentages work for any resolution and orientation; portrait phone videos are measured upright. Blur is a Gaussian blur whose strength (sigma) follows the picture size: 1.2%, 2.5%, 5% or 10% of the shorter side for light, medium, strong and maximum, and pixelation uses blocks of 1.5–10% of the shorter side. Logo removal (ffmpeg delogo) interpolates each pixel from the edge of the area; it leaves a soft patch and works best on small static logos over a calm background.

Example

On a 1920 × 1080 video, an area at left 70%, top 5%, width 25%, height 12% covers x = 1344, y = 54, 480 × 130 pixels, the top-right corner where channel logos usually sit. With "Strong" the blur sigma is 5% of 1,080 = 54 pixels, which makes text and faces unrecognisable.