This translation has not been editorially reviewed yet. The German version is authoritative. Deutsche Fassung
Accessibility
Why must a website stay calm when reached by keyboard?
A website must stay calm when reached by keyboard, because reaching an element is only a highlight — not yet a decision. Anyone jumping from element to element with the Tab key is looking around, like a customer walking along shelves in a shop. If a new page or window opens unprompted in the process, the visitor loses their orientation. WCAG criterion 3.2.1 forbids such surprises.
Reaching and triggering are two separate steps
With keyboard operation, a visible highlight — focus — moves to the next control element with every press of the Tab key. Only Enter triggers the highlighted element. This separation is vital for orientation for many people: blind visitors have every highlighted element read aloud first, before deciding. People with tremors sometimes land on elements accidentally. If the page already jumps when an element is highlighted — for example because a menu item loads its subpage the moment it's reached — these visitors can never get past it without changing pages. They're stuck as if in a revolving door that spins at every touch.
How the audit service measures behaviour on focus
The audit service operates your page in a real browser: it presses the Tab key, stop by stop, and logs every station the focus travels through. If the page's address changes during this journey — without Enter having been pressed — merely reaching the element has triggered a page change. The report treats that as a violation and names the address the measurement ended up on. If the journey passes through at least three stops with no such change, the criterion counts as passed. If the page offers fewer than three reachable stops, the measurement deliberately stays undecided, and the report marks the criterion as a manual check point.
Examples
Focus opens a window
<input name="plz" onfocus="zeigeHilfeDialog()"><input name="plz" aria-describedby="plz-hilfe">
<p id="plz-hilfe">Vier Ziffern, etwa 8010.</p>The focus moves across each element when going through Tab. If something happens, the visitor loses the position.
- Press the Tab key repeatedly on your homepage and watch whether the page stays put.
- Pay special attention to dropdown menus and language switchers — that's where triggering on reach is built in most often.
- Ask your agency to tie every action to a real interaction: Enter, spacebar, or click — never to merely being reached.
- Test again with the Tab key after adding any new menu or search component.
