Jernej LeticaPhotography Tools & Stories
Edit Photos

Pixelate Part of an Image

Draw over any part of a photo to turn it into square blocks. Add several areas, undo the last one and save a copy with the rest unchanged.

Built and written by Jernej Letica

Local browser processing No image upload No account required Blur saved into the pixels

How to pixelate part of an image

Pixelate works only on the parts you draw. Nothing outside the drawn areas is changed.

  1. Choose a photo. It opens in the editor with Pixelate already chosen under Effect and Rectangle under Shape.
  2. Drag over the part to hide. Choose Ellipse before you drag for a round area.
  3. Set Strength. A higher number gives bigger blocks, because the block size grows with the area you drew.
  4. Draw more areas if you need them. Press Undo last area to take back the last one, then press Download blurred photo.

Why the blocks are averaged, not just shrunk

Pixelating runs the same averaging as the blur tool, and shows each cell as one flat colour. Every cell of the area takes the average of its own pixels, and that average is written back over the cell. The detail inside a cell is gone from the saved pixels, so the block cannot be turned back into the text or the face it covered.

The block size comes from the area, not from the photo. At the lowest strength a cell is 3 % of the area's shorter side, and at the highest it is 27 %, never less than 2 pixels. Pixels outside the rectangle or the oval keep their values, so a PNG saved from this page changes only inside the areas you drew.

Blocks, blur and strength

Pixelate shows each cell in one flat colour, so the edges between blocks are sharp. The blur effect uses the same cells but blends between their centres, which looks softer. Choose Pixelate when the blocky look is the point, for a name badge or a number plate where a clear mosaic reads as hidden at a glance.

Strength is the only setting for block size. Pick it per area: a large area at strength 6 gets blocks wider than a small area at the same strength, because the blocks are a share of the area's own shorter side.

What a saved copy keeps

A PNG is saved from the edited pixels and then repacked without changing any value, so the blocks and the untouched parts are exact. A JPEG is rewritten only in the blocks under the areas, and the rest of the photo stays as it was. Undo changes only the preview, and nothing is saved until you press download.

Checks before you share the copy

  • Make the blocks big enough to hide the shape. A small area at a low strength can still show the outline of what it covers.
  • Draw a little beyond the edge of the thing you hide, so that no partial edge of it stays readable.
  • Pixelate a copy, not the original. The saved copy is the one you share, and the original keeps its detail.
  • Undo takes back the last area only. Select an earlier area and press Remove selected area to delete it.

Privacy

Your photo never leaves your device. The blur, the saving and the download all happen in your browser, and the copy you save carries none of the camera data or embedded preview of the original.

Frequently asked questions

How big are the blocks?

Each block is a share of the area's shorter side: 3 % at strength 1 and 27 % at strength 10, and never less than 2 pixels. A larger area therefore gets larger blocks at the same strength, and the blocks scale with the area rather than with the whole photo.

Can the pixelated part be restored?

No. Each block holds one average colour, so the detail inside a block is gone from the saved file. Keep the original if you need the unpixelated picture later.

Can I pixelate several parts of one photo?

Yes. Each drag adds one area with its own shape and strength, and the areas are applied in the order you drew them. The counter under the controls shows how many areas the photo has.

Why does undo remove only one area at a time?

Undo takes back the last area you drew, one press at a time, and it stops when no areas are left. To remove an earlier area, select it on the photo and press Remove selected area.

Is my photo uploaded when I pixelate it?

No. The photo is opened and pixelated in your browser, and no image data is sent anywhere. The only usage events the page reports name the tool and the effect you chose.

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