Image Blur Apply box blur to soften images with adjustable radius control.

What Is Image Blur?

An image blur tool softens an image by averaging neighboring pixel values using a convolution kernel. Box blur uses equal weights for fast, consistent results. This tool supports adjustable radius control so you can fine-tune the softening from a subtle haze to a heavy blur. Common uses include background softening for portrait-style depth of field, censoring sensitive information, and creating dreamy artistic effects. All processing is done client-side using Canvas API pixel manipulation.

Why Use Image Blur?

• Adjustable blur radius from subtle softening to heavy blur
• Box blur convolution for fast, consistent results
• Real-time preview of blur effect before downloading
• Client-side processing — images never leave your browser

Common Use Cases

Background Softening

Blur backgrounds to create depth-of-field portrait effects.

Privacy Protection

Blur faces, license plates, or sensitive information in photos.

Artistic Effects

Create dreamy, soft-focus effects for creative photography.

Thumbnail Backgrounds

Blur images for use as text overlay backgrounds in thumbnails.

Technical Guide

Box blur applies a convolution kernel where each element is 1/(size*size). For radius r, the kernel size is (2r+1)x(2r+1). Each output pixel is the average of all pixels within the kernel window. Edge pixels use reduced kernel areas.

Tips & Best Practices

• 1
  Use radius 1-3 for subtle softening, 5-10 for moderate blur, 15+ for heavy blur
• 2
  Blur is useful as a preprocessing step before adding text overlays
• 3
  Higher radius values take longer to process on large images
• 4
  Blurred images compress better because they contain less detail

Related Tools

Image Sharpen

Sharpen images with adjustable intensity using unsharp mask convolution.

🖼️ Image Tools

Image Pixelate

Pixelate images with adjustable block size for retro effects or privacy masking.

🖼️ Image Tools

Image Noise Reduce

Reduce noise and grain in images using median filtering.

🖼️ Image Tools

Image Tilt Shift

Create a miniature/tilt-shift effect by blurring above and below a focal band.

🖼️ Image Tools

Frequently Asked Questions

Q How does blur radius affect the result?

Higher radius means more pixels are averaged together, producing stronger blur.

Q Can I blur just part of an image?

This tool blurs the entire image. Crop the area first for selective blurring.

Q Does blurring reduce file size?

Yes, blurred images compress better because they contain less detail.

Q Can I undo the blur?

Blurring is destructive — it removes detail. Always keep your original file.

About This Tool

Image Blur is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.