Focus Order
If a web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability.
In plain language
When someone tabs through a page with the keyboard, the order things get focused in should follow a logical sequence that makes sense — not jump around randomly.
Why it matters
Keyboard and screen reader users experience the page one focused element at a time, in whatever order the code puts them in. If that order doesn't match the logical reading order, the page becomes confusing or even impossible to use correctly.
In practice
Fails this criterion
A form has fields grouped visually by section (name, address), but pressing Tab jumps between unrelated fields in a scrambled order — from the name field to a checkbox, then back to an address field.
Meets this criterion
Pressing Tab moves through the form in the same logical order the fields are grouped and displayed, section by section, matching what a sighted user would expect.
Test it yourself
Tab through a page from the very top and follow where focus goes (a visible outline usually shows it). Does the order make sense, following the page's logical structure? If it jumps around unpredictably, this criterion is failing.