Apply an Adjustable Gaussian Blur Across an Image

About the Blur Image Tool

The blur strength slider runs from 1 to 40 pixels and starts at 6. At the low end the effect is a light softening that still leaves the subject recognisable; by the time you reach the twenties, text and faces have dissolved into shapes. That upper range is genuinely useful when the goal is to prove an image exists without letting anyone read what is in it.

One thing to be clear about before you start: the blur is applied to the entire image, not to a region you select. There is no brush and no selection box, so this cannot soften a single face while leaving the rest sharp. If your aim is to remove one specific detail from a picture, cropping it away is both simpler and safer, because cropped pixels are genuinely gone. Where an all-over treatment is what you want, everything is computed in the browser and the original never travels.

Key Features

• Radius from 1 to 40 pixels: A single slider takes you from barely-there softening to a completely illegible image.
• Live strength preview: The blur redraws as you drag, so the exact point where detail stops being readable is easy to find.
• Applies to the whole frame: The effect is uniform across the image, which is what you want for backdrops and deliberate obfuscation.
• Format and quality control: Export as PNG, JPG or WebP with a quality slider, or keep the input format.
• Several images at once: Apply a consistent radius across a set and download them together.

How to Use the Blur Image Tool

1. Add the image you want to soften.
2. Drag the blur strength slider and watch the preview.
3. For an unreadable result, keep raising the radius until no text or feature can be made out at full size.
4. Pick an output format and export.

How It Works

The blur is a Gaussian applied by the browser's compositor to the drawing context before the image is painted onto the output canvas, with your slider value passed straight through as the radius in pixels. Because it is handled by the graphics pipeline rather than a script loop, even a large radius on a large photograph completes quickly. Two caveats: the filter samples beyond the canvas boundary, so the outermost edge can feather slightly toward transparency, and the effect cannot be confined to a region — the transform has no concept of a selection, so partial blurring is outside what this tool does.

When You Need It

A consultancy writing a public case study wants to show the analytics dashboard it built for a client, but every figure on that screen is commercially confidential. Blurring the whole screenshot heavily leaves an image that still reads as a dashboard while making the numbers genuinely unrecoverable. Since the unblurred original contains the client's trading data, producing that illustration through an online editor would defeat the purpose entirely. Designers building frosted backdrops for a hero section and teams generating placeholder imagery use lighter radii for purely visual reasons.