WCAG 2.2 success criterion 1.3.1 Info and Relationships (Level A)
Headings form the outline screen reader users navigate by. Jumping from H2 straight to H4 suggests a missing section and makes the structure harder to follow.
Who it affects: Screen reader users, who jump from heading to heading to understand and skim a page, and people with cognitive disabilities who rely on clear structure.
A heading more than one level deeper than the one before it. The post title is treated as the page's H1, as nearly every theme shows it.
Check ID heading-skipped-level — use it to filter the content report or with wp lumtera issues --rule.
Choose heading levels by structure, not by size: sections of the post are H2, sub-sections inside them H3, and so on. To change how a heading looks, change its font size in the block settings instead of its level.
In the block editor, this issue has a Fix button: one click repairs the block, and Undo puts it back.
Lumtera runs this check in the block editor sidebar as you write, in the Elementor panel, in Review mode on the live page, and across the whole site in the content report and with wp lumtera scan. You can change its severity or turn it off in Accessibility → Settings.
All 64 checks, the editor sidebar, Elementor panel and site report — free, with no account and no page limits.