{{APIRef("High Resolution Time")}}
The Performance
interface represents timing-related performance information for the given page.
An object of this type can be obtained by calling the {{domxref("Window.performance")}} read-only attribute.
Note: This interface and its members are available in Web Workers, except where indicated below. Note that some available parts of the interface are not yet documented (see the Performance Timeline and User Timing specs for more details.) Also note that performance markers and measures are per context. If you create a mark on the main thread (or other worker), you cannot see it in a worker thread, and vice versa.
Properties
The Performance
interface doesn't inherit any properties.
- {{domxref("Performance.timing")}} {{readonlyInline}} {{NotAvailableInWorkerInline}}
- Is a {{domxref("PerformanceTiming")}} object containing latency-related performance information.
- {{domxref("Performance.navigation")}} {{readonlyInline}} {{NotAvailableInWorkerInline}}
- Is a {{domxref("PerformanceNavigation")}} object representing the type of navigation that occurs in the given browsing context, like the amount of redirections needed to fetch the resource.
- {{domxref("Performance.onresourcetimingbufferfull")}}
- Is an {{domxref("EventTarget")}} which is a callback that will be called when the {{event("resourcetimingbufferfull")}} event is fired.
Methods
The Performance
interface doesn't inherit any method.
- {{domxref("Performance.now()")}}
- Returns a {{domxref("DOMHighResTimeStamp")}} representing the amount of milliseconds elapsed since a reference instant.
- {{domxref("Performance.toJSON()")}} {{NotAvailableInWorkerInline}}
- Is a jsonizer returning a json object representing the
Performance
object. - {{domxref("Performance.getEntries()")}}
- Returns a list of {{domxref("PerformanceEntry")}} objects based on the given filter.
- {{domxref("Performance.getEntriesByType()")}}
- Returns a list of {{domxref("PerformanceEntry")}} objects of the given entry type.
- {{domxref("Performance.getEntriesByName()")}}
- Returns a list of {{domxref("PerformanceEntry")}} objects based on the given name and entry type.
- {{domxref("Performance.clearResourceTimings()")}}
- Removes all {{domxref("PerformanceEntry","performance entries")}} with a {{domxref("PerformanceEntry.entryType","entryType")}} of "
resource
" from the browser's performance data buffer. - {{domxref("Performance.setResourceTimingBufferSize()")}}
- Sets the browser's resource timing buffer size to the specified number of "
resource
" {{domxref("PerformanceEntry.entryType","type")}} {{domxref("PerformanceEntry","performance entry")}} objects.
Specifications
Specification | Status | Comment |
---|---|---|
{{SpecName('Highres Time Level 2', '#the-performance-interface', 'toJSON()')}} | {{Spec2('Highres Time Level 2')}} | Defines toJson() method. |
{{SpecName('Highres Time', '#the-performance-interface', 'Performance')}} | {{Spec2('Highres Time')}} | Defines now() method. |
{{SpecName('Navigation Timing', '#sec-window.performance-attribute', 'Performance')}} | {{Spec2('Navigation Timing')}} | Defines timing and navigation properties. |
{{SpecName('Performance Timeline Level 2', '#extensions-to-the-performance-interface', 'Performance extensions')}} | {{Spec2('Performance Timeline Level 2')}} | Changes getEntries() interface. |
{{SpecName('Performance Timeline', '#sec-window.performance-attribute', 'Performance extensions')}} | {{Spec2('Performance Timeline')}} | Defines getEntries() , getEntriesByType() and getEntriesByName() methods. |
{{SpecName('Resource Timing', '#extensions-performance-interface', 'Performance extensions')}} | {{Spec2('Resource Timing')}} | Defines clearResourceTimings() and setResourceTimingBufferSize() methods and the onresourcetimingbufferfull property. |
{{SpecName('User Timing Level 2', '#extensions-performance-interface', 'Performance extensions')}} | {{Spec2('User Timing Level 2')}} | Clarifies mark() , clearMark() , measure() and clearMeasure() interfaces. |
{{SpecName('User Timing', '#extensions-performance-interface', 'Performance extensions')}} | {{Spec2('User Timing')}} | Defines mark() , clearMark() , measure() and clearMeasure() interfaces. |
Browser compatibility
{{CompatibilityTable}}
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support (timing attribute) |
6.0 | {{CompatGeckoDesktop("7.0")}} | 9.0 | 15.0 | 8 |
navigation attribute |
{{CompatChrome("9")}} | {{CompatGeckoDesktop("7")}} | 9.0 | {{CompatOpera("15")}} | 8 |
now() on regular context |
{{ CompatChrome("20.0") }} {{ property_prefix("webkit") }} {{ CompatChrome("24.0") }} |
{{ CompatGeckoDesktop("15.0") }} | 10.0 | {{CompatVersionUnknown()}} | 8 |
now() in Web workers. |
{{ CompatChrome("33.0") }} | {{ CompatGeckoDesktop("34.0") }} | {{CompatUnknown}} | {{ CompatVersionUnknown() }} | {{CompatNo}} |
toJSON() |
{{CompatNo}} | {{CompatGeckoDesktop("25.0")}} | 9.0 | {{CompatNo}} | {{CompatNo}} |
getEntries() , getEntriesByType() , getEntriesByName() |
{{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatNo}} |
clearResourceTimings() , setResourceTimingBufferSize() |
{{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatNo}} |
onresourcetimingbufferfull |
{{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatNo}} | {{CompatVersionUnknown}} | {{CompatNo}} |
mark() , clearMark() , measure() , clearMeasure() |
43 | 41 | 10 | 33 | {{CompatNo}} |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | {{CompatNo}} | {{CompatGeckoMobile("7.0")}} | {{CompatGeckoFxOS("7.0")}} | 9.0 | 15.0 | 9 |
navigation attribute |
{{CompatNo}} | {{CompatNo}} | {{CompatNo}} | 9.0 | {{CompatVersionUnknown}} | 9 |
now() on regular context |
{{ CompatChrome("20.0") }} {{ property_prefix("webkit") }} {{ CompatChrome("24.0") }} |
{{ CompatGeckoMobile("15.0") }} | {{ CompatGeckoFxOS("15.0") }} | 10.0 | {{CompatVersionUnknown}} | 9 |
now() in Web workers. |
{{CompatUnknown}} | {{ CompatGeckoMobile("34.0") }} | {{CompatUnknown}} | {{CompatUnknown}} | {{CompatUnknown}} | {{CompatUnknown}} |
toJSON() |
{{CompatNo}} | {{CompatGeckoMobile("25.0")}} | {{CompatGeckoFxOS("25.0")}} | 10.0 | {{CompatNo}} | {{CompatUnknown}} |
getEntries() , getEntriesByType() , getEntriesByName() |
{{CompatVersionUnknown}} | {{CompatGeckoMobile("25.0")}} | {{CompatGeckoFxOS("25.0")}} | 10.0 | 33 | {{CompatNo}} |
clearResourceTimings() , setResourceTimingBufferSize() |
{{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatVersionUnknown}} | 33 | {{CompatNo}} |
onresourcetimingbufferfull |
{{CompatVersionUnknown}} | {{CompatVersionUnknown}} | {{CompatUnknown}} | {{CompatNo}} | 33 | {{CompatNo}} |
mark() , clearMark() , measure() , clearMeasure() |
46 | 42 | 42 | 10 | 33 | {{CompatNo}} |