Chrome devtools emulate vision deficiencies is a feature that many web developers and designers do not know about, but it is incredibly useful for building accessible websites. If you have ever wondered how your website looks to someone with color blindness or other vision challenges, Chrome DevTools has a built-in way to show you exactly that. This tool is free, easy to use, and can help you create a more inclusive web experience for everyone.
Let me explain what this feature does, why it matters, and how you can start using it right away.
Why Vision Deficiency Emulation Matters
When you build a website, it is easy to assume that everyone sees it the same way you do. But the reality is that millions of people around the world have some form of vision deficiency. This includes color blindness, which affects approximately 8 percent of men and 0.5 percent of women of Northern European descent. Other vision conditions include blurred vision, reduced contrast sensitivity, and difficulty distinguishing between certain colors.
If your website relies heavily on color alone to convey information, you might be excluding a significant portion of your potential audience. For example, if you use red and green to indicate error and success states, people with red-green color blindness might not be able to tell the difference. If your contrast ratios are too low, people with reduced vision might struggle to read your content. These are not minor issues. They can mean the difference between someone being able to use your website or leaving in frustration.
The good news is that Chrome DevTools makes it simple to see your website through different eyes. By emulating various vision deficiencies, you can identify problems before they become real issues for your users.
How to Access Vision Deficiency Emulation in Chrome DevTools
Using this feature is straightforward, and you do not need any special technical knowledge to get started. Here are the steps to follow.
First, open Chrome DevTools on any website. You can do this by right-clicking anywhere on the page and selecting Inspect, or by pressing Command+Option+I on Mac or Control+Shift+I on Windows. Once DevTools is open, look for the three dots in the upper right corner of the DevTools window. Click on those dots to open the menu, then select More tools and choose Rendering. This will open a new panel with various options.
Within the Rendering panel, scroll down until you find a dropdown menu labeled Emulate vision deficiencies. Click on that dropdown, and you will see a list of different vision conditions you can emulate. These include options like Protanopia, which simulates red color blindness, Deuteranopia, which simulates green color blindness, and Tritanopia, which simulates blue color blindness. You can also choose options like Achromatopsia, which simulates complete color blindness, and blurred vision, which simulates reduced visual acuity.
Select any of these options, and your website will immediately change to show how it appears to someone with that particular vision deficiency. The change applies only to what you see in your browser. Other people viewing the site will not be affected.
What to Look For When Testing
Once you have the emulation turned on, it is time to examine your website critically. Here are some key things to check.
Start with your color scheme. Look for places where color is used to convey meaning. This might include form validation messages, status indicators, links versus regular text, or charts and graphs. Ask yourself whether someone who cannot distinguish between certain colors would still understand the information being presented. If not, consider adding additional cues like icons, text labels, or patterns to reinforce the meaning.
Next, check your contrast ratios. Good contrast makes text easy to read for everyone, but it is especially important for people with vision challenges. Make sure your text stands out clearly against its background. There are online tools that can help you check contrast ratios, but you can often get a sense of the problem just by looking through the emulation.
Also, look at your images and icons. If you use images that convey important information, think about whether someone with a vision deficiency would be able to understand them. Alt text helps screen readers, but it does not help someone using the emulation feature. Consider whether your images need additional context or whether you should use different visuals.
Finally, test your interactive elements. Buttons, links, and form fields should be clearly distinguishable. If you rely on color alone to indicate which element is focused or hovered, you might want to add other visual cues like underlines, borders, or background changes.
Common Problems and How to Fix Them
When you start emulating vision deficiencies, you will likely discover some issues on your website. Here are the most common problems and simple fixes for each.
One common issue is using red and green together. This is particularly problematic for people with red-green color blindness. The fix is simple. Add another indicator besides color. For example, you can add a checkmark or X icon, or use different shapes or positions to convey the same meaning.
Another common problem is low contrast between text and background. This affects not only people with color blindness but also anyone viewing your site in bright sunlight or on a poorly calibrated screen. The solution is to increase the contrast. Dark text on a light background or light text on a dark background works best. Aim for a contrast ratio of at least 4.5 to 1 for normal text.
A third issue is relying on color to indicate status. If your dashboard uses color-coded status indicators, make sure each status is also identifiable by position, label, or icon. This way, color becomes an enhancement rather than the only method of communication.
Making Accessibility a Habit
The best approach to accessibility is to think about it from the beginning of your design process rather than trying to fix problems later. When you are creating a new design or building a new feature, take a moment to check it through the vision deficiency emulation. This habit will save you time and effort in the long run, and it will result in a better experience for all your users.
It is also worth remembering that accessibility benefits everyone, not just people with diagnosed vision deficiencies. Older adults, people using mobile devices in bright sunlight, and anyone with temporary vision problems all appreciate good contrast and clear visual cues. By designing for accessibility, you are ultimately designing for a better experience for everyone.
A Helpful Tool for Browser Management
While you are working on improving accessibility, you might also find that managing many open tabs helps you focus on the task at hand. If you often have dozens of tabs open while testing different aspects of your website, consider using a tool that helps organize them. Tab Suspender Pro is an extension that can automatically suspend tabs you are not currently using, which frees up memory and can make your browser feel faster and more responsive. It is a small change that can make a big difference in your workflow.
Tips from the team behind Tab Suspender Pro and the Zovo extension suite at zovo.one