Performance
The Performance
interface represents timing-related performance information for the given page.
An object of this type can be obtained by calling the 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.
Performance.navigation
Read only- Is a
PerformanceNavigation
object representing the type of navigation that occurs in the given browsing context, like the amount of redirections needed to fetch the resource. Not available in workers. Performance.onframetimingbufferfull
- TBD
Performance.onresourcetimingbufferfull
- Is an
EventTarget
which is a callback that will be called when theresourcetimingbufferfull
event is fired. Performance.timing
Read only- Is a
PerformanceTiming
object containing latency-related performance information. Not available in workers.
Methods
The Performance
interface doesn't inherit any method.
Performance.clearFrameTimings()
- TBD
Performance.clearMarks()
- Removes the given mark from the browser's performance entry buffer.
Performance.clearMeasures()
- Removes the given measure from the browser's performance entry buffer.
Performance.clearResourceTimings()
- Removes all
performance entries
with aentryType
of "resource
" from the browser's performance data buffer. Performance.getEntries()
- Returns a list of
PerformanceEntry
objects based on the given filter. Performance.getEntriesByName()
- Returns a list of
PerformanceEntry
objects based on the given name and entry type. Performance.getEntriesByType()
- Returns a list of
PerformanceEntry
objects of the given entry type. Performance.mark()
- Creates a
timestamp
in the browser's performance entry buffer with the given name. Performance.measure()
- Creates a named
timestamp
in the browser's performance entry buffer between two specified marks (known as the start mark and end mark, respectively). Performance.now()
- Returns a
DOMHighResTimeStamp
representing the amount of milliseconds elapsed since a reference instant. Performance.setFrameTimingBufferSize()
- TBD
Performance.setResourceTimingBufferSize()
- Sets the browser's resource timing buffer size to the specified number of "
resource
"type
performance entry
objects. Performance.toJSON()
- Is a jsonizer returning a json object representing the
Performance
object.
Specifications
Specification | Status | Comment |
---|---|---|
High Resolution Time Level 2 The definition of 'toJSON()' in that specification. |
Recommendation | Defines toJson() method. |
High Resolution Time The definition of 'Performance' in that specification. |
Recommendation | Defines now() method. |
Navigation Timing The definition of 'Performance' in that specification. |
Recommendation | Defines timing and navigation properties. |
Performance Timeline Level 2 The definition of 'Performance extensions' in that specification. |
Candidate Recommendation | Changes getEntries() interface. |
Performance Timeline The definition of 'Performance extensions' in that specification. |
Recommendation | Defines getEntries() , getEntriesByType() and getEntriesByName() methods. |
Resource Timing Level 1 The definition of 'Performance extensions' in that specification. |
Candidate Recommendation | Defines clearResourceTimings() and setResourceTimingBufferSize() methods and the onresourcetimingbufferfull property. |
User Timing Level 2 The definition of 'Performance extensions' in that specification. |
Working Draft | Clarifies mark() , clearMark() , measure() and clearMeasure() methods. |
User Timing The definition of 'Performance extensions' in that specification. |
Recommendation | Defines mark() , clearMark() , measure() and clearMeasure() methods. |
Unknown The definition of 'Performance extensions' in that specification. |
Recommendation | Defines clearFrameTimings() , setFrameTimingBufferSize() , and onframetimingbufferfull methods. |
Browser compatibility
BCD tables only load in the browser