DevDockTools
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Accessibility Toolkit

Engineer accessible UIs with a comprehensive toolkit. Simulate four types of color blindness, analyze WCAG contrast ratios, inspect focus order, and get ARIA role guidance — all in one panel.

No color vision deficiency

Normal Vision
E
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Note: colors-only status indicators may be invisible to color-blind users → always add text/icons.
Normal vision
E
Error notification
Your form has 3 errors
Active
Inactive
Pending
Note: colors-only status indicators may be invisible to color-blind users → always add text/icons.
Design guidelines for color blindness
• Never use color as the only indicator — add text, icons, or patterns
• Red/green combinations are problematic for ~8% of men
• Use high contrast within each color in addition to the colors themselves
• Test your UI with the simulator to catch issues early

Frequently Asked Questions

What types of color blindness are simulated?

The tool simulates protanopia (no red cones), deuteranopia (no green cones), tritanopia (no blue cones), and achromatopsia (complete color blindness) using clinically validated RGB transformation matrices.

What is the minimum WCAG contrast ratio?

WCAG 2.1 AA requires 4.5:1 for text under 18pt (14pt bold), and 3:1 for larger text. AAA requires 7:1 for normal text. These ratios ensure readability for people with low vision.

What are ARIA roles?

ARIA (Accessible Rich Internet Applications) roles describe the purpose of UI elements to assistive technologies like screen readers. Use them when native HTML semantics aren't available — but prefer native elements first.

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