Certvo research
WCAG 2.1 failure rates by success criterion
The share of 1,564 real websites with at least one automated failure against each WCAG 2.1 success criterion, from the Certvo Web Accessibility Report 2026. 16 criteria were detected by the scanner (11 at Level A, 5 at Level AA); criteria that automated tools cannot evaluate are not listed and should not be read as passing.
| Rank | Criterion | Name | Level | Sites affected | % of sites |
|---|---|---|---|---|---|
| 1 | 4.1.2 | Name, Role, Value | A | 1,049 | 67.1% |
| 2 | 1.4.3 | Contrast (Minimum) | AA | 803 | 51.3% |
| 3 | 2.4.4 | Link Purpose (In Context) | A | 784 | 50.1% |
| 4 | 1.1.1 | Non-text Content | A | 467 | 29.9% |
| 5 | 1.3.1 | Info and Relationships | A | 351 | 22.4% |
| 6 | 1.4.4 | Resize Text | AA | 232 | 14.8% |
| 7 | 2.1.1 | Keyboard | A | 105 | 6.7% |
| 8 | 2.1.3 | — | A | 105 | 6.7% |
| 9 | 3.1.1 | Language of Page | A | 72 | 4.6% |
| 10 | 1.4.1 | Use of Color | A | 66 | 4.2% |
| 11 | 2.4.2 | Page Titled | A | 27 | 1.7% |
| 12 | 1.3.5 | Identify Input Purpose | AA | 4 | 0.3% |
| 13 | 2.2.2 | Pause, Stop, Hide | A | 3 | 0.2% |
| 14 | 3.1.2 | — | AA | 3 | 0.2% |
| 15 | 1.4.12 | Text Spacing | AA | 2 | 0.1% |
| 16 | 2.2.1 | Timing Adjustable | A | 1 | 0.1% |
Download this table as CSV · Source: Certvo Web Accessibility Report 2026, automated scan of 1,564 websites (2026-03-16 to 2026-09-06).
Reading this table
A website is counted once per criterion regardless of how many failing elements it has, so the percentages answer "how many sites have this problem at all", not "how much of the web is broken". One issue can map to more than one criterion: a link with no accessible name fails 2.4.4 Link Purpose and 4.1.2 Name, Role, Value together, which is one reason 4.1.2 sits at the top.
Only machine-testable criteria appear. Success criteria such as 1.3.3 Sensory Characteristics, 2.4.3 Focus Order or 3.3.3 Error Suggestion require a person to judge, so their absence from this table says nothing about how often they fail. Treat the figures as a floor for each criterion listed and as no information at all for the ones that are not.
Each criterion links to its explainer, which covers what the criterion requires, who it affects, the common failure patterns and a copyable fix. The methodology behind the numbers is on the methodology page; the narrative and the other tables are in the full report.