Blur an image
One slider takes a picture from slightly soft to fully frosted. The blur is even in every direction and is measured against the size of the picture, so it looks the same on a phone photo and on a small web graphic.
- Runs in your browser
- Nothing is uploaded
- No sign-up
- Batch up to 20 images
Drag & drop your image here
or tap to browse · you can also paste from the clipboard
JPG · PNG · WebP · GIF · BMP · AVIF · SVG · up to 50 MB each · up to 20 files
Choose imagesBefore
After
Processed image will appear here.
How to use the image blur tool
Add the picture and move the Blur strength slider. Around 20 gives a clear, even blur, 40 gives a frosted-glass look that works behind text, and 70 or more leaves only shapes and colour. The whole image is blurred, and the result downloads in its original format.
- Add your imageIt is blurred straight away at a moderate strength, so you can see the effect.
- Move the sliderLow numbers soften, high numbers leave only shapes and colour.
- DownloadKeep the original format, or pick JPG, PNG or WebP.
About this tool
A blurred picture is useful more often than it sounds. It makes a calm background for text, hides detail in something you are only using as decoration, and takes the edge off a harsh image. This page blurs the whole picture evenly, the effect photo editors call a Gaussian blur.
The slider does not count pixels. A 20 pixel blur wrecks a thumbnail and does almost nothing to a 12 megapixel photo, so the strength here is a share of the picture's longer side. Set it once and a batch of differently sized images comes out looking alike. The exact radius in pixels is shown with each result.
What you get
- Even blur in every direction, from soft to frosted
- Strength follows the picture's size, not a pixel count
- Keeps transparent areas in PNG and WebP
- Batch up to 20 images with one setting
- Runs on your device, with no upload
When to use the image blur tool
Backgrounds for text
A blurred photo behind a heading or a slide keeps the mood of the picture without competing with the words on top of it.
Website hero and placeholder images
A heavily blurred version of a photo makes a small, quick-loading stand-in that can be swapped for the sharp one once it arrives.
Softening a harsh or noisy picture
A strength of 3 to 8 takes the edge off grain and compression speckle without making the picture look out of focus.
Abstract colour washes
At the top of the slider any photo turns into a smooth gradient of its own colours, useful as a wallpaper or a card background.
What each strength does
| Strength | Radius on a 4000 px photo | Radius on a 1000 px image | Looks like |
|---|---|---|---|
| 5 | about 4 px | about 1 px | Barely soft; smooths grain |
| 20 | about 17 px | about 4 px | Clearly blurred, shapes easy to read |
| 40 | about 48 px | about 12 px | Frosted glass; good behind text |
| 70 | about 114 px | about 28 px | Only large shapes and colour remain |
| 100 | 200 px | 50 px | A wash of colour |
How it works
The blur is a Gaussian blur: every pixel becomes a weighted average of the pixels around it, with nearer ones counting for more. It is computed as three passes of a plain moving average in each direction, a standard shortcut whose result is within a few percent of the exact bell-shaped curve and takes the same time whatever the radius. Where a picture has transparent areas, colours are weighted by how opaque they are while they are averaged, so a cut-out does not pick up a dark fringe from the invisible pixels around it.
The slider is turned into a radius between 0.05% and 5% of the picture's longer side. A strong blur removes all fine detail by definition, so for radii above a few pixels the work is done on a reduced copy of the picture, which is then enlarged again; the outcome is the same and it is many times faster on a large photo. The result is re-encoded as a new file, which means the original's metadata is not carried over.
Common problems and how to fix them
- I cannot see any blur
- At low strengths on a large photo the blur is only a few pixels wide and the preview is shown much smaller than the file. Raise the slider, or use the zoom buttons under the picture to look at it at 100%.
- I only wanted to blur one part
- This page blurs the whole frame. Use Censor Image, place a box on the part you mean and choose Blur.
- The edges of the picture look slightly different
- A blur needs pixels on every side of each point, and at the border there are none beyond it, so the edge pixels are repeated outwards. With a very strong blur this can make the outermost strip a little more even in colour. Cropping a thin margin removes it.
- A big photo takes a while
- Images over 24 megapixels are not processed on every slider movement. Set the strength, then press Apply changes.
Frequently asked questions
How do I blur only part of an image?
Use the Censor Image tool. You drag a box over the area, choose Blur, and the rest of the picture is left as it is. This page always blurs the whole picture.
Can a blurred image be made sharp again?
Not from the blurred file. Blurring averages neighbouring pixels together, and the fine detail that was averaged away is not stored anywhere in the result. Keep your original if you might need it.
Why does the same number look different in another editor?
Most editors ask for a radius in pixels, which means the look depends on how large the image is. Here the number is a share of the picture's longer side. The result panel shows the radius in pixels that was used, which you can type into an editor to match it.
Does blurring make the file smaller?
Usually, yes. JPG, WebP and PNG all store smooth areas in fewer bytes than detailed ones, and a blurred picture is all smooth areas. A heavy blur often halves the size of a JPG at the same quality setting.
What is the strongest blur I can apply?
At 100 the radius is 5% of the picture's longer side, which is 200 pixels on a 4000 pixel photo. Nothing recognisable survives that. If you need even more, run the result through the tool a second time.
Does it work on transparent PNGs?
Yes. The transparent areas stay transparent, and the edge of the visible part fades out smoothly instead of ending in a hard line. Download as PNG or WebP to keep that; JPG has no transparency and fills it with the background colour you choose.