Comparison
Keyboard operabilityvsTab order
Keyboard operability
you put the mouse away and tried to complete the whole flow with Tab, Enter, Space and the arrow keys.
The requirement that every function be reachable and usable from the keyboard alone. It matters far beyond screen readers: switch access, voice control and anyone with a temporary injury depend on the same path. Testing it takes minutes and finds most of what an audit would find, which makes it the highest-yield habit in this whole section.
Full entry →Tab order
you tabbed through the form and the order jumped around because a CSS grid had reordered the fields visually.
The sequence in which focusable elements receive focus, which follows DOM order, not visual order. `tabindex="0"` puts a non-focusable element into that order and `-1` makes it focusable only by script; any positive value jumps the queue and reliably breaks it. Flexbox `order` and grid placement change what you see without changing the order you tab through, which is the most common way this goes wrong.
Full entry →