A Color-Vision Deficiency Simulator: Benchmark 2025

"Web accessibility" takes you way beyond alt text for images or testing ARIA labels. One of the most neglected topics is how CVD users perceive interfaces. In 2025, several accessibility testing tools simulate how people with various types of color blindness see websites. But how good are these simulators, and how do they measure up in relation to WCAG and inclusive design principles?

This paper compares the most common simulators used, discussing how they work and provide information to designers who are developing accessible web design.

Why Color-Vision Simulators Are Relevant to Accessibility

An estimated 300 million people around the world have some type of color-vision deficiency. For some of these people, bad UI designs with low contrast or color-only cues provide a huge usability barrier.

Key reasons simulators matter:

• Validate semantic HTML and visual elements against WCAG guidelines

• Guide accessibility audits by detecting risky color patterns

• Support ADA compliance efforts for digital products

• Provide designers with empathy through simulated user personas experiencing CVD

By combining simulators with a color contrast checker, teams can better ensure inclusive design.

Benchmark Methodology

We tested five leading simulators on key criteria relevant to web accessibility:

1. Fidelity of simulation: Does the tool accurately match the experience of CVD?

2. Interoperability with Accessibility Testing Tools: To what extent are the components Buddha has been built for (e.g., React components) able to be used in pairs with other systems, such as Lighthouse or the more general axe suite?

3. Standardized wording & terminologies for crafting Alt tags, as well as the best colors and typefaces, make it easier to see why some choices come out well when others flop completely. Moreover, an automatic wizard provides tips on how these things can be improved even further--thus preventing any hasty decision that might lead to a white elephant.

4. Developer Experience: Ease of integration with design or semantic HTML systems

So each of the simulators had a standardised accessibility audit. This includes test pages written in different color schemes, font faces, and alt texts for images as a direct comparison.

2025 Simulator Benchmark Results

These findings highlight that while most simulators provide valuable user insights, their reliability varies. Designers should not rely on them as the sole source of truth for accessible web design.

Beyond Simulators – Building Inclusive Systems

Simulators are tools, not replacements for rigorous design practices. Teams should combine them with:

• Accessibility audits powered by automated and manual reviews

• A color contrast checker integrated into design pipelines

• Accessibility testing tools like Axe and Pa11y

• Inclusive design patterns that reduce dependency on color alone

• Proper use of aria labels and semantic HTML

This layered approach ensures accessibility is not an afterthought but part of continuous delivery.

Conclusion

Our survey results reveal that none of the simulators in 2025 were good at pre-existing color vision deficiency. At the same time, they have been pushed as complements to accessibility-analysis software in helping identify areas of trouble points beyond basic GUI checking: lacking these, nothing will work except sumptuous WCAG 2.0 myth-breaking articles on every rule in the game.

From accessible webpage design with alt text for images, aria labels, and semantic HTML, teams producing world-scalable apps must consider the importance of non-visual information Some day, a one-size-fits-all app version will not be for everyone! Ultimately, genuine accessibility comes about through frequent validation, shows of empathy, and the use of inclusive design methodologies.