How to Do a Blur Test: Step-by-Step Guide for Designers
Learn how to perform a blur test (squint test) on your designs with step-by-step instructions for testing visual hierarchy.
What is a Blur Test?
A blur test (sometimes called a squint test) removes fine details from a design, leaving only the fundamental visual elements: shapes, colors, and contrast.
When you blur a design:
Text becomes illegible
Small icons disappear
Only dominant visual elements remain visible
What survives the blur is what users process first—in the pre-attentive stage of visual perception, before conscious thought kicks in.
Why Blur Testing Works
Our brains process visual information in two stages:
Pre-attentive processing (under 500ms)
We perceive shapes, colors, and movement without conscious effort
Attentive processing
We focus on details, read text, and make decisions
Blur testing simulates pre-attentive processing. It shows you what registers in that crucial first half-second.
Method 1: The Manual Blur Test
Using Your Eyes (Squint Test)
The simplest approach requires no tools at all:
Display your design at full size on screen
Step back 2–3 feet from your monitor
Squint your eyes until the image becomes blurry
Note what elements you can still identify
Using Photoshop or Figma
In Photoshop:
Open your design
Go to Filter → Blur → Gaussian Blur
Set radius to 8–15 pixels
Observe what remains visible
Method 2: AI-Powered Blur Testing
Modern tools like BlurTest combine blur testing with AI analysis to provide:
Objective attention heatmaps
Predicted eye-tracking paths
Specific recommendations for improvement
Comparison tools for A/B variants
What to Look for in a Blur Test
1. Is the most important element the most visible?
Your primary CTA, main headline, or key product image should dominate when blurred.
2. Are there competing focal points?
Multiple elements of equal visual weight create confusion. One element should clearly dominate.
3. Does the hierarchy match your goals?
If your goal is signups, the signup button should stand out. Match visual hierarchy to business objectives.
Common Blur Test Findings
CTAs that disappear
Buttons with colors too similar to the background
Decorative image dominance
Stock photos overpowering the message
Text-heavy designs
Everything at equal visual weight
Navigation stealing focus
Header elements more prominent than main content
Key Takeaways
Blur tests reveal what users see in the first 500ms
Manual methods work but AI tools provide objective analysis
Your most important element should dominate when blurred
Test at multiple blur levels and on multiple devices