UtilibyWritten by the Utiliby editorial team · Last updated October 13, 2026 · Rules and formulas reviewed October 2026
What this free blur image tool does
You often need to share a picture but not everything in it: a face in a crowd, a license plate, an address on a letter, a name on a screenshot or the numbers on a card. This free online blur image tool lets you hide those parts in your browser. Draw a box, an ellipse or a brush stroke over the area, choose blur, pixelate or a solid box, and save the result.
It can also do the reverse and blur the whole picture except the area you choose, which gives a simple focus effect. The picture is never uploaded, there is no sign-up and the saved file has no watermark.
How to blur part of an image in four steps
- Add your image. Drop a JPG, PNG, WebP or other image onto the drop area, or click to choose it.
- Choose the area tool and effect. Rectangle suits text and plates, Ellipse suits faces and Brush suits odd shapes. Pick Blur, Pixelate or Solid box.
- Draw over the area. Drag on the picture. The effect shows at once. Draw as many areas as you need, and use Undo if you make a mistake.
- Download. Choose PNG, JPG or WebP and press Download image.
Blur, pixelate or solid box?
| Effect | Looks like | Best for | Safety |
|---|---|---|---|
| Blur | Soft smear | Backgrounds, faces in a crowd, casual privacy | Medium at high strength, low at light strength |
| Pixelate | Colored squares | Faces and plates when you want the classic look | Low at small block sizes, medium at large ones |
| Solid box | Flat color | Passwords, card and ID numbers, addresses, names | High: the pixels are replaced |
Safety here means how hard it is to recover the hidden detail. Even strong effects leave some information, so for truly sensitive content always choose the solid box.
Why light blur is not enough
Blur and pixelation do not delete a picture, they transform it. Because the process follows fixed rules, software can sometimes estimate what was underneath, especially for text with a known font or for large, clear faces. Researchers have shown that pixelated text and numbers can be guessed. A solid box does not have this problem, because the original pixels are replaced with a single color and cannot be rebuilt.
Practical rules: use a solid box for text and numbers, use a high strength for faces, cover the whole sensitive area with some margin, and look at the saved file zoomed in before you share it. If you edit a screenshot, save a new file rather than keeping layers or an editable copy.
Blurring the background
To make a subject stand out, draw an ellipse or a brush stroke over it and tick Blur everything except the chosen areas. The rest of the picture is blurred. This is a simple approximation of a shallow depth of field. It does not detect edges, so draw carefully around the subject and use a medium strength to keep the result natural.
Common uses
- Privacy in photos: hide faces of bystanders and children before you post.
- Screenshots: hide names, email addresses, account numbers and tokens.
- Documents: cover the details on an ID, a letter or a receipt that are not needed.
- Street scenes: blur license plates and house numbers.
- Product photos: hide a background or a label.
- Social posts: make a clean blurred background behind a focal point.
Tips for hiding information properly
- Cover with a margin: draw past the edges of the text or face.
- Choose Solid box for text: it is the only fully safe option.
- Check metadata: use the EXIF Data Remover to delete hidden location data.
- Zoom in to check: open the saved image at full size.
- Share a new file: do not share the original or a layered project file.
- Think about context: clothes, tattoos and surroundings can identify a person.
Troubleshooting
- Nothing happens when I drag: the area must be at least a few pixels. Drag a larger box.
- The blur looks too weak: raise the strength or use a solid box.
- The whole picture is blurred: Blur everything except the chosen areas is ticked.
- I cannot undo an old area: Undo removes the last area first. Use Clear all areas to start again.
- The picture will not open: HEIC opens only in Safari. Try another format or a smaller file.
Online blur tool or photo editor?
Photo editors offer layers, smart selection, face detection and non-destructive filters. They are the right choice when you need a precise cut-out or a lot of edits. A browser blur tool is faster for the simple, common job of hiding one or two details before you share a picture. You open the page, draw over the area and save a new file, with nothing to install and no account.
It also keeps the picture on your device. That matters most for the images people want to blur: IDs, bills, messages and photos of other people. A tool that uploads the file to a server would defeat the purpose, because a copy of the unblurred original would travel to a stranger's computer first. Here the original never leaves your browser tab, and closing the tab discards it.
One limit to keep in mind: this tool applies one effect to all of the chosen areas and works on one image at a time. If you need to hide dozens of faces in a large set of photos, a dedicated editing workflow may be quicker.
Privacy and how it works
Your browser opens the picture and draws it onto a canvas. The blur is computed on your device from the pixels, a mask made from your areas decides where it shows, and the result is saved as a new file. Nothing is uploaded, stored or logged. The saved file has no EXIF metadata.
Frequently asked questions
How do I blur part of an image online for free?
Add your picture, choose Rectangle, Ellipse or Brush, and drag over the part you want to hide. Set the strength and press Download image. Everything runs in your browser.
How do I blur a face in a photo?
Choose the Ellipse tool, drag over the face, and raise the strength. For a person who must not be recognized, use a strong blur or the Solid box effect, because a light blur can still be recognizable.
Is my image uploaded anywhere?
No. Your browser opens the image and applies the effect on your own device. Nothing is sent to Utiliby or to any other server.
Is blur a safe way to hide text or numbers?
Not always. Light blur and coarse pixelation can sometimes be partly reversed or guessed, especially for text. For passwords, card numbers or ID numbers, use the Solid box effect, which replaces the pixels completely.
What is the difference between blur and pixelate?
Blur softens detail by mixing nearby pixels. Pixelate replaces the area with large colored squares. Both reduce detail. A solid box covers the area with one color and hides everything.
How do I blur a license plate?
Use the Rectangle tool over the plate and set a high strength, or choose Solid box. Plates are small, so check the result at full size before you share it.
Can I blur the background and keep the subject sharp?
Yes. Draw an ellipse or brush stroke over the subject and tick Blur everything except the chosen areas. The effect covers the rest of the picture.
Can I blur more than one area?
Yes. Each time you drag, another area is added with the current effect. Use Undo to remove the last area, Redo to bring it back, or Clear all areas to start again.
What does the Brush tool do?
It paints the effect freehand, which suits irregular shapes like hair, a hand or a handwritten line. Use the brush size slider to change the width.
Can I use a different effect on different areas?
The effect applies to all areas at once and you can change it any time before you download. To mix effects, download once with one effect, load the result, and add the next effect.
Does it work on a phone?
Yes. Draw with your finger on the picture. Very large photos may use a lot of memory on older phones. If the image does not open, try a smaller one.
Will the quality of the rest of the image change?
The unblurred areas keep their original pixels. If you save as JPG or WebP, the whole image is compressed again, so use PNG or a quality of 90 or above for the best result.
Which file formats can I use?
You can open JPG, PNG, WebP, GIF, BMP, AVIF and SVG images that your browser supports and save PNG, JPG or WebP. HEIC opens only in Safari.
Can I change the color of the solid box?
Yes. Choose Solid box and pick any color. Black and white are the most common choices for covering information.
Does the saved image keep location data?
No. The edited image is drawn fresh and saved without EXIF metadata, so camera details and GPS location are not included.
How strong should the blur be?
For a background, a medium strength is enough. For anything people should not recognize or read, use a high strength or a solid box, then look at the result zoomed in.
What can I print or save from the page?
Print / save summary gives a page with the settings and a preview. Copy summary copies the settings as text. The edited image is the main download.
Sources and further reading
- MDN Web Docs, Canvas API and compositing operations, for how masks and effects are drawn in the browser.
- Hill, Mariani and others, research on recovering pixelated and blurred text and faces, for why light effects are not a safe way to hide information.
- MDN Web Docs, Image file type and format guide, for PNG, JPEG and WebP.
- Electronic Frontier Foundation, Surveillance Self-Defense, guidance on sharing photos safely.
Sources were consulted in October 2026. Standards and rules can change, so always check the official page for your situation.