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Axe Core Guide

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Find out what web pages on your sites are affected by HTML issues.

Axe Core 4.6

Users should be able to zoom and scale the text up to 500%

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.

The option user-scalable="no" within the content attribute of the <meta name="viewport"> element prevents page zooming.

The maximum-scale setting restricts the user’s ability to zoom. This is troublesome for individuals with low vision who rely on screen magnifiers to view web page content.

Users with partial or low vision frequently choose to increase their browser’s fonts to make web content easier to read. Everything visible in the browser window at a given time is the viewport focus. If the user maximizes the browser on a high-resolution display, the viewport’s focus area is expansive and may encompass the entire online page.

If the browser window is small, only a small portion of the web page is visible in the viewport focus region. The viewport focus of the browser has no effect on the programmatic focus. Users can scroll the web page up and down, but the focus does not follow the viewport. Developers are required by the Web Content Accessibility Guidelines to build pages to enable resizing up to 200%; nevertheless, it is considered best practice to demand a 5x zoom.

What this Accessibility Rule Checks

Ensures that the user-scalable="no" parameter is absent from the <meta name="viewport"> element, and that the maximum-scale parameter is greater than or equal to 500%

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Related Accessibility Rules