Navigation timing confidenceLimited availability
The confidence property of a navigation performance entry describes whether the navigation metric is likely to be representative the page's performance (high confidence) or affected by transient conditions, such as browser startup (low confidence).
Not yet supported in all major browsers — check the table and provide a fallback.
Browser support
DesktopChrome
1–144Not supported
145+Supportedsince Feb 10, 2026
Current: 155Edge
12–144Not supported
145+Supportedsince Feb 14, 2026
Current: 154Firefox
✕Not supportedup to 157
Current: 157Safari
✕Not supportedup to 27
Current: 27MobileChrome Android
18–144Not supported
145+Supportedsince Feb 10, 2026
Current: 155Firefox Android
✕Not supportedup to 157
Current: 157Safari iOS
✕Not supportedup to 27
Current: 27How to use
Not supported in Firefox, Safari, Firefox Android, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.
Example
Full syntax and examples are on MDN: confidence.
Feature detection
JS · check before using
if ("PerformanceNavigationTiming" in globalThis && "confidence" in PerformanceNavigationTiming.prototype) {
// PerformanceNavigationTiming.confidence is available
}Specification
Sub-features
Support for each part of the feature (5). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| PerformanceNavigationTiming.confidence | 145 | 145 | ✕ | ✕ | 145 | ✕ | ✕ |
| PerformanceTimingConfidence | 145 | 145 | ✕ | ✕ | 145 | ✕ | ✕ |
| PerformanceTimingConfidence.randomizedTriggerRate | 145 | 145 | ✕ | ✕ | 145 | ✕ | ✕ |
| PerformanceTimingConfidence.toJSON | 145 | 145 | ✕ | ✕ | 145 | ✕ | ✕ |
| PerformanceTimingConfidence.value | 145 | 145 | ✕ | ✕ | 145 | ✕ | ✕ |