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Responsive
How big must buttons on a website be at minimum?
Buttons and links should be at least 24 by 24 pixels — that's what accessibility rule WCAG 2.5.8 requires. Smaller areas are hard to hit with a finger: anyone who taps wide on mobile lands on the wrong link, or gives up. The audit service measures every control across four device sizes, and shows examples of areas that are too small along with their measured size.
These areas count as controls
What's measured is everything visitors can click or tap: buttons, links, input fields, and dropdown lists. Links in the middle of running text are exempt — their height comes from the line of text, which the standard explicitly allows too. Also exempt are invisible helper elements a few pixels in size that some websites build in for screen readers or analytics; they're not targets for a finger, and counting them would create false alarms. What's left are exactly the areas a person actually has to hit: the order button, the menu item, the search icon, the email address field. The minimum of 24 by 24 pixels applies to each of these.
How the audit service measures the size
The page is built in a real browser at four device sizes: smartphone at 390, tablet at 768, desktop at 1440, and wide at 1920 pixels wide. At every size, the check measures the actually rendered width and height of every control. That matters, since the same button can be large enough on desktop and shrink on mobile. Every finding is collected twice; only what both measurements agree on gets reported. The report shows up to three examples with the measured size — a button at 18 by 18 pixels, say — and a screenshot of the affected spot, so the area is found without searching.
What the minimum size does for your visitors
Large controls primarily help people with tremors, limited fine motor control, or bigger fingers. But they help everyone: on a moving train, wearing gloves, with the thumb of the one free hand. Anyone who hits a button on the first try stays in flow — anyone who misses three times leaves the page. For a business, that means, very practically: the "Request a quote" button gets pressed more often when it's easy to hit. The 24 pixels here are the standard's minimum, not an ideal value; many designers deliberately choose noticeably larger areas, especially for a page's most important button.
- Tap your website's most important buttons on mobile with your thumb, and check whether you hit them on the first try.
- Pay special attention to small icons: the search icon, menu, phone receiver, arrows in image galleries.
- Pass the examples from the audit report on to your agency — it states the measured size of every area that's too small.
- Have new buttons planned at at least 24 by 24 pixels from the start.
FAQ
What does WCAG 2.5.8 say about button size?
Rule 2.5.8 of the WCAG accessibility guideline requires a minimum size of 24 by 24 pixels for controls. Exemptions include links in running text, whose height is dictated by the line of text. The rule belongs to level AA, which the audit service follows. Larger areas are explicitly allowed and usually the better choice.
Why are buttons that are too small a problem?
Small areas are hard to hit with a finger. Visitors tap wide, open the wrong link, or give up. People with limited fine motor control are affected first, but in practice, so is everyone using a phone on the go. A button that's easy to hit noticeably more often leads to the desired action — an inquiry or a call, say.
Do links within text also count as controls?
The check exempts links in the middle of running text, since their height comes from the line of text — the standard provides for that too. What's measured are standalone controls: buttons, menu items, icons, and input fields. A visitor has to specifically hit exactly these areas, which is why the minimum size of 24 by 24 pixels applies there.