What this tool can — and can't — tell you
It can
- Build quick visual empathy for how color and contrast choices land for real users
- Flag obvious color-only signals (e.g. a red/green status dot with no icon or text)
- Give designers and stakeholders a fast, concrete "aha" moment
It can't
- Check WCAG 2.1 AA contrast ratios or any other success criterion
- Diagnose an individual's actual vision or replace a real assistive-tech test
- Tell you whether your site is legally compliant
Vision deficiency statistics
A real screenshot, six honest filters
The simulator loads your page in a real headless browser, exactly like our accessibility scanner does, and takes a single screenshot. Everything after that happens in your browser: each condition is applied as a CSS/SVG filter over the same image, so switching between them is instant and nothing extra is sent anywhere. Protanopia, deuteranopia and tritanopia use published color-transformation matrices; achromatopsia converts the image to grayscale by luminance; low vision applies a soft blur; low contrast sensitivity flattens contrast and lifts brightness slightly. None of these are medical-grade simulations — they're deliberately simple approximations, good enough to build empathy and catch the obvious color-only mistakes, not to replace a real assistive-technology test or a WCAG audit.
If a status indicator, a form error, or a call-to-action button disappears or becomes hard to read under one of these filters, that's a signal worth investigating — usually it means color alone is carrying information that should also be carried by text, an icon, or a pattern. That's exactly the kind of finding our full accessibility scanner checks for automatically, alongside dozens of other WCAG 2.1 AA rules.
Frequently asked questions
Is the Vision Simulator a real accessibility test?
No. It's a visual empathy tool that shows an approximation of how your page might look under different vision conditions. It doesn't check WCAG success criteria, contrast ratios, or anything code-level — for that, use Abledly's free accessibility scanner.
How accurate are the color-blindness filters?
They use published color-transformation matrices commonly used to approximate protanopia, deuteranopia, tritanopia and achromatopsia. They're a reasonable visual approximation, not a medical simulation or diagnostic tool — real color vision deficiency varies a lot between individuals.
Does this check color contrast against WCAG?
No. This tool is about building visual empathy and catching obvious issues at a glance. Abledly's free accessibility scanner runs real WCAG 2.1 AA contrast checks (plus dozens of other rules) against your live page with two engines and AI review.
Is my screenshot stored anywhere?
No. The screenshot is captured, returned to your browser for display, and not saved to a database.
What conditions does the simulator show?
Protanopia, deuteranopia and tritanopia (three types of color vision deficiency), achromatopsia (complete color blindness), a low-vision blur approximation, and a low-contrast-sensitivity approximation — alongside the unfiltered original.
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