Top 10 Accessibility Issues
Web developers worldwide have found 93 million A11Y issues on 12 million checked web pages.
Here are the most common issues detected by Rocket Validator.
Last update: Thursday, December 4, 2025
1. All page content should be contained by landmarks. 78.77%
The recommended practice is to keep all content, excluding skip links, in designated areas such the header, nav, main, and footer.
2. Heading levels should only increase by one. 7.33%
The h1 through h6 element tags must be in a sequential order for headings to be in a correct logical order.
3. Landmarks should have a unique role or role/label/title (i.e. accessible name) combination. 6.07%
Landmarks must have an unique role or role/label/title (i.e. accessible name) combination.
4. Document should have one main landmark. 2.94%
A best practice is to guarantee that there is only one primary landmark for navigating to the page’s principal content, and if the page has iframe components, each should contain either no landmarks or a single landmark.
5. Page should contain a level-one heading. 1.92%
To enable screen reader users to navigate the heading structure with keyboard shortcuts rather than wasting time listening to more of the website to understand its structure, make sure the page, or at least one of its frames, contains a h1 element that appears before the start of the main content.
6. Aside should not be contained in another landmark. 1.14%
Ensure the complementary landmark or <aside> is at top level.
7. Zooming and scaling must not be disabled. 0.81%
The user-scalable="no" parameter in the <meta name="viewport"> element must not be used since it prevents text scaling and zooming, which are necessary for individuals with impaired vision.
8. Document should not have more than one banner landmark. 0.38%
Ensure there is only one “banner” landmark at most on the page.
9. Document should not have more than one main landmark. 0.37%
The core content of the page should only have one main landmark, and if the page contains iframe components, each one should either have no landmarks or just one. This is considered best practice.
10. Main landmark should not be contained in another landmark. 0.27%
Best practice dictates that the primary landmark should not be enclosed within another landmark. All content must be contained within discrete areas, such as the header (role="banner"), body (role="main"), and footer (role="contentinfo").
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