IIS adoption & performance trends
2 quarters of aggregate data
Unique domains per quarter
Median composite score
Median Lighthouse performance
Median Lighthouse accessibility
How this is calculated
Each point is the median across all public IIS audits completed that quarter. Quarters with fewer than 3 audits are skipped.
Learn more about our methodology →Raw data
| Quarter | Unique domains | Composite | Performance | Accessibility |
|---|---|---|---|---|
| Q2 '26 | 61 | 71 | 44 | 88 |
| Q3 '26 | 4 | 79 | 43 | 86 |