Automated testing is a valuable tool; it can quickly find most occurrences of certain issues, with a thoroughness that would be very difficult to achieve manually.
Most of these issues are related to coding practices; for example, automated testing can quickly check if all image content (such as
<img> elements) have text alternatives, which are needed by screen reader users.
Unfortunately, automated testing can only detect 10 to 40% of accessibility issues; furthermore, automated tools can lead to false negatives (not detecting an issue), as well as false positives (reporting something that’s not actually a problem).
Since accessibility practices are designed to meet the needs of real people, most issues need to be manually tested by a human. For example, while automated testing can detect if text alternatives are present, only a person can check if these text alternatives are properly written and actually deliver the information they are supposed to. You can learn more about this on our text alternatives page.
- Building the most inaccessible site possible with a perfect Lighthouse score by Manuel Matuzo (2019)
- aXe testing tool by Deque
- Lighthouse testing tool by Google
- Siteimprove Accessibility Checker Chrome extension by Siteimprove
- Siteimprove, a service that provides analytics, including accessibility, on deployed sites