This translation has not been editorially reviewed yet. The German version is authoritative. Deutsche Fassung →
Accessibility
Must text on a website be zoomable to 200 percent?
Yes: visitors must be able to zoom your website's text to 200 percent — that is, double the size — without losing content or functionality. Many people with declining eyesight read with a zoomed-in view as a matter of course. Browser zoom handles this on its own, as long as the website doesn't lock it out or break when zoomed in.
Browser zoom is the web's reading glasses
Anyone who struggles to read small text presses Ctrl and plus on a computer, or spreads two fingers apart on a phone — and the page grows. For many older visitors, that's the normal way to read websites at all. The rule requires that nothing gets lost up to double the size: text mustn't overlap, buttons mustn't move off screen, content mustn't get cut off. The most common and most frustrating violation is the zoom lock on phones: a code setting that completely forbids the two-finger zoom gesture. It usually comes from old templates and can be removed in minutes — the benefit for visitors with impaired vision is enormous.
How our measurement engine checks zoomability
Our measurement engine reads out your page's display setting and reliably detects zoom locks: if the code forbids zooming on a phone or caps it below double the size, the report flags that as a serious finding with a precise explanation. The check also notes whether your page offers its own font-size switcher — that's a nice extra, but it doesn't replace a working browser zoom. Whether the page reflows cleanly when actually zoomed in is closely tied to the related reflow criterion, which our measurement engine measures at several screen widths. The overall judgment on behaviour at 200 percent is made at the Gold Standard level by a human who operates the zoomed-in page.
- Press Ctrl and plus on your website until you reach 200 percent — all content and buttons must stay usable.
- Test the two-finger zoom gesture on a phone — if it doesn't work, have the zoom lock removed from the code.
- Ask your agency to set font sizes in flexible units instead of fixed pixel values.
- After zooming in, check menus and forms especially closely — that's where things break first.
- Never rely solely on your own font-size switcher: browser zoom must always work as well.
FAQ
How do visitors zoom in on a website's text?
On a computer with Ctrl and plus, or Cmd and plus on a Mac; on a phone and tablet by spreading two fingers apart. Both are built-in browser features. The website must allow this zoom and handle it up to double the size without losing content or functionality.
What is a zoom lock, and why is it harmful?
A code setting that forbids or heavily restricts zooming on a phone. Visitors with impaired vision then simply can't read the page. The lock usually comes from outdated templates and can be removed quickly. Our measurement engine detects it automatically and flags it in the report as a serious finding.
Is a font-size switcher on the website enough?
Not as the sole solution. A switcher on the page is a nice extra, but the rule requires that ordinary browser zoom works — that's what visitors know and use. Our report notes an existing switcher positively, but independently checks whether browser zoom is unobstructed.