Blur

Blur image tool

Details

How to use Blur image tool

What the tool does, how to run it, and what to expect from the result.

How to blur part of an image

Blur softens a region. It is an aesthetic tool, not a security one: use it for backgrounds and bystanders, and use an opaque box for anything that must not be read.

The edit is applied destructively to a canvas and exported as a new flattened file, so no original pixels survive under the blurred area.

  • Upload the image you want to edit.
  • Drag a rectangle over the area to obscure.
  • Set the blur radius, remembering that a small radius on structured content leaves it recoverable.
  • Repeat for as many regions as you need, since each selection is applied independently.
  • Export as PNG, then check the result at full zoom before you share it, and consider deleting the original.

Why blur is often the cleanest edit

Blur works well when the goal is to hide a detail without making the edit feel too harsh. It softens the sensitive part while keeping the overall image readable and intact.

That makes it useful for screenshots, photos, product captures, and social images where the hidden area should fade into the background instead of looking aggressively boxed out.

What this page should help with

This is best when someone already knows they want blur and does not need a broader editor first. The job is simply: open the image, select the area, blur it, and export.

  • Blurring faces in everyday photos
  • Softening numbers and names in screenshots
  • Hiding addresses, order details, or account data
  • Cleaning up interface captures before publishing
Tips

Getting a better result out of Blur image tool

Specific settings and thresholds, not general advice.

  • Blur is the weakest form of redaction and it should not be used on text. A Gaussian blur is a reversible mathematical operation in principle, and for a known font, a limited character set and a known blur radius, an attacker can render every candidate string, blur it the same way, and match the result. Use the black box tool for anything readable.
  • Where blur is appropriate is aesthetic obscuring: softening a background, a bystander, a brand logo or a licence plate in a photo you are publishing for reasons other than security.
  • The blur radius here defaults to 18 pixels and it is applied to a rectangular selection you drag. A radius that is small relative to the text height leaves the letter shapes recoverable, so if you insist on blurring text, use a radius several times the cap height.
  • The export is a flattened raster. The tool draws the source image into a canvas, paints the blur over those pixels, and encodes a completely new file, so the exported image has no layers and no original pixel data hiding under the blurred region.
  • Re-encoding through a canvas also drops the source file's EXIF, including GPS coordinates and the camera serial. That is a side effect of the process, but it is a real one, and it means the exported file is cleaner than the original in more ways than the visible one.
Limits

What Blur image tool does not do

The honest boundary, so you do not lose time finding it yourself.

  • It does not detect faces, plates or text. You drag rectangles by hand over everything you want blurred.
  • The selection is rectangular only. There is no lasso, no brush and no circular mask.
  • It cannot guarantee that blurred text is unrecoverable, because blur of text is not a secure redaction.
  • It does not delete the original file. The unredacted image is still sitting on your disk after you export.
Reference

Terms used on this page

Short, plain-language definitions for the formats and settings above.

At a glance

Who Blur image tool is for

A quick way to understand who this helps, what it solves, and where it connects next.

Best fit

People hiding faces, names, numbers, addresses, interface details, and background subjects before sharing an image

Ideal for

Softening sensitive parts of a photo or screenshot without removing the whole section or sending the file to a server

FAQ

Common questions

Short answers for the questions people usually have before trying a utility like this.

When is blur better than pixelation?

Blur is better when you want the hidden area to feel softer and less visually harsh while still making the sensitive detail unreadable.

Does this upload images anywhere?

No. The image stays in the browser while you blur the selected area and export the result.

Can I blur only one part of the image?

Yes. The tool uses rectangular selection, so you can blur exactly the part you want and leave the rest untouched.

Can blurred text be recovered?

Sometimes, yes. A Gaussian blur is a known, reversible transform. If an attacker knows the font, the approximate size and the blur radius, they can generate candidate strings, apply the same blur, and compare. It has been demonstrated repeatedly on redacted screenshots. For text, use an opaque box.

When is blur the right choice?

When you want to de-emphasise rather than hide: a busy background, a bystander's face in a crowd photo, a competitor's logo. If the consequence of someone recovering the content is serious, blur is the wrong tool.

Does the exported file still contain the original pixels?

No. The image is drawn into a canvas, the blur is painted over those pixels, and a new file is encoded from the result. There is no layer stack and no hidden original underneath, which is the difference between this and a black rectangle drawn in a PDF or a slide deck.

What blur radius should I use?

It defaults to 18 pixels. For obscuring a face at a distance that is plenty. For anything with structure, the radius needs to be large relative to the feature you are hiding, several times the height of a character if it is text.

Does the image get uploaded?

No. The image is decoded and processed on a canvas in your browser and downloaded directly. Nothing is sent to a server, which is the only sensible way to handle a file you are redacting.

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