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Shaishav Patel
Shaishav Patel

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How to Blur Part of an Image Free — Blur a Face, License Plate, or Specific Area Without an App

You have a photo with a face in it. Or a license plate. Or an account number visible in a screenshot. You need to blur just that part — not the whole image.

Most free tools only blur the entire image. Fotor and BeFunky put selective (regional) blur behind paid plans.

The Image Blur Tool at Ultimate Tools adds a Select Area mode free. Draw a rectangle over any region, set the blur intensity, and download. Add as many regions as you need — all in one pass.


How to Blur Only Part of an Image

  1. Open the free selective blur tool
  2. Upload your photo (JPG, PNG, WebP supported)
  3. Click the Select Area tab
  4. Click and drag on the image to draw a rectangle over the area to blur
  5. Add more rectangles as needed (face, plate, address — all in one pass)
  6. Adjust blur intensity: Subtle (3px), Medium (10px), Heavy (25px), or custom slider up to 50px
  7. Click Download Image

Each region is listed below the image with its dimensions and a delete button. You can remove individual regions and re-draw them.


How It Works Technically

The tool uses the browser's Canvas API. For each defined region:

  1. The original image is drawn on a full-size canvas
  2. A clipping rectangle is applied to that region
  3. ctx.filter = "blur(Xpx)" is set and the image is redrawn only inside the clip — the rest stays sharp
  4. The clip is released and the next region is processed

This means the blur is applied pixel-accurate to the selected rectangle. No blur bleeds outside the region because the canvas clip prevents it.

All processing runs locally in your browser. The image is never uploaded to any server.


How Strong Should the Blur Be?

Use case Recommended blur Why
Face for privacy 20–25px (Heavy) Facial features become unrecognizable
License plate 15–25px Numbers become unreadable
Account number / address 10–15px Text becomes illegible
Background element 5–10px Visible but not distracting

For legal or journalistic use where identity must be fully protected, use 25–50px. At 25px, individual features are no longer distinguishable.


Multiple Regions — All in One Download

Each drag creates a new numbered region. You can blur a face, a license plate, and a visible address all at once:

  • Region 1 → face (top-left of image)
  • Region 2 → license plate (bottom-right)
  • Region 3 → name visible in the background

All three blur regions are applied before you download, so the final image contains all three blurred areas in a single file. No need to run the tool multiple times.


Compared to Paid Tools

Tool Selective blur Price
Fotor Yes Paid plan
BeFunky Yes Paid plan
Canva Limited (shape mask) Paid plan
Ultimate Tools Yes — unlimited regions Free

No signup, no watermark, no export limit. The image never leaves your browser.


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