WQI.web​qualityindex
Method v1.2.0 86 live / 86 total factors methodology

methodology / Accessibility / #55

Heading hierarchy validity

#55 · Required · Web Standards · accessibility · Accessibility · weight 0.7% · impl implemented · method v1.2.0

Web Standards item — Accessibility

This factor is part of Web Standards — the table-stakes binary layer of the score. It is graded pass/fail and gates the Web Quality score; it is not weighted into Web Quality itself.

Pass criteria
Tolerant — passes on pass or warn.
Web Standards label
Valid heading hierarchy
Why it's required
Headings are how assistive tech navigates the page. A page with no H1 or with H1→H4→H2 leapfrog isn't navigable.
Same factor, two depths.

What we measure

Page headings should descend in order — H1, then H2s, then H3s. Skipping levels (jumping H1 to H4) breaks how screen readers navigate the page.

How to improve your score

Audit your headings and renumber so they're sequential. Most pages should have one H1, several H2s, and H3s only nested inside an H2.

Facts

Ticket
WEBQ-55
Category
Accessibility
Status
live
Weight
0.7%
Data source
Service cost
Free HTML parsing
Scoring impl
implemented
Method version
v1.2.0

Implementation notes

Parse heading tags in document order, check for skipped levels and multiple H1s.

Scoring

Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.

Cited by these standards

Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.

Version history

Version Change Date
v1.2.0 Factor introduced. Status: live. Scoring impl: implemented. 2026-04-25

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