There must only be one main landmark to navigate to the primary content of the page, even if the page contains iframes.

Rule ID: landmark-one-main
Ruleset: axe-core 3.0
User Impact: Moderate
WCAG: Best practice

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Compliance Data & Impact

User Impact

Disabilities Affected

  • Blindness
  • Deafblindness
  • Mobility/Dexterity


  • Best Practice

WCAG Success Criteria

  • Not specified or not applicable

Section 508 Guidelines

  • Not specified or not applicable

How to Fix the Problem

Ensure there is a navigation point to the primary content of the page. If the page contains iframes, each iframe should contain either no main landmarks or just one.

Ensure all content is contained within a landmark region, designated with HTML5 landmark elements and/or ARIA landmark regions.

It is a best practice to use both HTML 5 and ARIA landmarks to ensure all content is contained within a navigational region. In HTML5, you should use elements like <header>, <nav>, <main>, and <footer>. Their ARIA counterparts are role=”banner”, role=”navigation”, role=”main”, and role=”contentinfo”, in that order. By using both HTML5 and ARIA markup, you make the webpage more robust and functional no matter what screen reader technology is used.

Once this markup is added, screen reader users will be able to navigate to a section based on its ARIA landmark or HTML element. This provides a simple replacement for a skip navigation link, though the replacement is only useful for users of screen readers. Sighted users or users of screen enlargers wouldn’t get much benefit from the addition, so it can’t replace skip navigation links altogether.


A simplified web page, stripped down to just the bare landmark essentials, might look something like this:

<header role="banner">
   <p>Put company logo, etc. here.</p>
<nav role="navigation">
      <li>Put navigation here</li>
<main role="main">
   <p>Put main content here.</p>
<footer role="contentinfo">
   <p>Put copyright, etc. here.</p>

The markup for regions and roles is redundant, but this is a transition period, and the above markup is the most robust.

Why this is Important

Navigating a web page is far simpler for screen reader users if all of the content is split between a number of high level sections. Content outside of these sections is difficult to find and its purpose may be unclear.

HTML has historically lacked some key semantic markers, such as the ability to designate sections of the page as the header, navigation, main content, and footer. Using both HTML5 elements and ARIA landmarks in the same element is considered a best practice, but the future will probably favor HTML regions as browser support increases.

Rule Description

It is a best practice to ensure that there is only one main landmark to navigate to the primary content of the page, and that if the page contains iframes, each should either contain no landmarks, or just a single landmark.

The Algorithm (in simple terms)

Ensures that all content on a page is contained within a landmark region


Other Resources

You may also want to check out these other resources.

Refer to the complete list of axe 3.0 rules.