Top 10 Accessibility Issues
Web developers worldwide have found 97 million A11Y issues on 12 million checked web pages.
Here are the most common issues detected by Rocket Validator.
Last update: Wednesday, March 11, 2026
1. All page content should be contained by landmarks. 78.92%
All page content should be wrapped inside landmark regions such as <header>, <nav>, <main>, and <footer>. When content sits outside these landmarks, screen reader users may struggle to find it or understand its purpose. To fix this, ensure every visible element on the page (except skip navigation links) is contained within an appropriate landmark element.
2. Heading levels should only increase by one. 6.79%
Heading levels must increase sequentially — an h1 should be followed by an h2, not an h3 or h4. Skipping heading levels breaks the logical document outline that assistive technology users rely on to understand and navigate page content. To fix this, restructure your headings so they form a proper hierarchy without gaps.
3. Landmarks should have a unique role or role/label/title (i.e. accessible name) combination. 4.86%
When a page contains multiple landmarks with the same role (such as two <nav> elements or two <aside> elements), each must be given a unique accessible name so users can distinguish between them. Without unique names, screen reader users who navigate by landmarks cannot tell which landmark is which, making it difficult to jump to the correct section of the page.
4. Document should have one main landmark. 2.61%
Every web page should have exactly one main landmark so screen reader users can quickly jump to the primary content. If the page contains iframe elements, each iframe should have either no main landmark or exactly one. Add a <main> element (or a container with role="main") to wrap your page’s principal content, and ensure all other visible content is placed inside appropriate landmark regions as well.
5. Aside should not be contained in another landmark. 2.44%
The <aside> element (or any element with role="complementary") must be placed at the top level of the document, not nested inside another landmark region. To fix this, move the <aside> or role="complementary" element outside of any containing landmarks such as <main>, <nav>, <header>, <footer>, or other sectioning elements with landmark roles.
6. Zooming and scaling must not be disabled. 1.93%
The <meta name="viewport"> element must not include user-scalable="no", and the maximum-scale parameter must not be set to a value less than 2. These settings prevent or limit zooming, which is essential for users with low vision who rely on pinch-to-zoom or screen magnification to read content. Remove user-scalable="no" and ensure maximum-scale is at least 2 (or omit it entirely) to allow users to resize content up to at least 200%.
7. Page should contain a level-one heading. 1.51%
Every page should contain a level-one heading (h1) to give screen reader users a reliable landmark for jumping directly to the main content. Without an h1, users who rely on assistive technology must listen through large portions of the page to understand its structure. Add a single h1 element at the beginning of your main content to fix this issue.
8. Document should not have more than one banner landmark. 0.56%
A page must not contain more than one banner landmark. When multiple banner landmarks exist, screen reader users cannot reliably distinguish the site-wide header from other content, making landmark-based navigation confusing and unreliable. To fix this, ensure your page has at most one element with role="banner" or one top-level <header> element that serves as the banner landmark.
9. Banner landmark should not be contained in another landmark. 0.20%
The banner landmark (created by a top-level <header> element or role="banner") must be a top-level landmark and not nested inside another landmark such as main, navigation, or complementary. When a banner is buried within another landmark, screen reader users cannot reliably locate the site-wide header using landmark navigation. To fix this, move the banner landmark outside of any containing landmark so it sits directly under the <body> element.
10. Document should not have more than one main landmark. 0.17%
A page should have only one main landmark so that screen reader users can quickly and reliably navigate to the primary content. If your document contains multiple main landmarks — whether from <main> elements or elements with role="main" — assistive technology users may become confused about where the primary content actually begins. To fix this, ensure your page has exactly one <main> element (or one role="main"), and if the page includes <iframe> elements, each iframe should contain either no main landmark or just one.
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