High Resolution Time API

Method to provide the current time in sub-millisecond resolution and such that it is not subject to system clock skew or adjustments. Called using performance.now()

Spec https://www.w3.org/TR/hr-time/
Status W3C Recommendation
IE Edge Firefox Chrome Safari Opera
      98    
    95 97    
    94 96 TP  
11 95 93 95 15 80
10 94 92 94 14.1 79
9 93 91 93 14 78
8 92 90 92 13.1 77
Show all
7 91 89 91 13 76
6 90 88 90 12.1 75
5.5 89 87 89 12 74
  88 86 88 11.1 73
  87 85 87 11 72
  86 84 86 10.1 71
  85 83 85 10 70
  84 82 84 9.1 69
  83 81 83 9 68
  81 80 81 8 67
  80 79 80 7.1 66
  79 78 79 7 65
  18 77 78 6.1 64
  17 76 77 6 63
  16 75 76 5.1 62
  15 74 75 5 60
  14 73 74 4 58
  13 72 73 3.2 57
  12 71 72 3.1 56
    70 71   55
    69 70   54
    68 69   53
    67 68   52
    66 67   51
    65 66   50
    64 65   49
    63 64   48
    62 63   47
    61 62   46
    60 61   45
    59 60   44
    58 59   43
    57 58   42
    56 57   41
    55 56   40
    54 55   39
    53 54   38
    52 53   37
    51 52   36
    50 51   35
    49 50   34
    48 49   33
    47 48   32
    46 47   31
    45 46   30
    44 45   29
    43 44   28
    42 43   27
    41 42   26
    40 41   25
    39 40   24
    38 39   23
    37 38   22
    36 37   21
    35 36   20
    34 35   19
    33 34   18
    32 33   17
    31 32   16
    30 31   15
    29 30   12.1
    28 29   12
    27 28   11.6
    26 27   11.5
    25 26   11.1
    24 25   11
    23 24   10.6
    22 23 (*)   10.5
    21 22 (*)   10.0-10.1
    20 21 (*)   9.5-9.6
    19 20 (*)   9
    18 19    
    17 18    
    16 17    
    15 16    
    14 15    
    13 14    
    12 13    
    11 12    
    10 11    
    9 10    
    8 9    
    7 8    
    6 7    
    5 6    
    4 5    
    3.6 4    
    3.5      
    3      
    2      
Safari on iOS Opera Mini Android Browser Blackberry Browser Opera Mobile Android Chrome Android Firefox IE Mobile Android UC Browser Samsung Internet QQ Browser Baidu Browser KaiOS Browser
15 all 94 10 64 94 92 11 12.12 15.0 10.4 7.12 2.5
14.5-14.8   4.4.3-4.4.4 7 12.1     10   14.0      
14.0-14.4   4.4   12         13.0      
13.4-13.7   4.2-4.3   11.5         12.0      
Show all
13.3   4.1   11.1         11.1-11.2      
13.2   4   11         10.1      
13.0-13.1   3   10         9.2      
12.2-12.5   2.3             8.2      
12.0-12.1   2.2             7.2-7.4      
11.3-11.4   2.1             6.2-6.4      
11.0-11.2                 5.0-5.4      
10.3                 4      
10.0-10.2                        
9.3                        
9.0-9.2                        
8.1-8.4                        
8                        
7.0-7.1                        
6.0-6.1                        
5.0-5.1                        
4.2-4.3                        
4.0-4.1                        
3.2                        

Notes

The timestamp is not actually high-resolution. To mitigate security threats such as Spectre, browsers currently round the result to varying degrees.

  1. In Firefox, the "privacy.reduceTimerPrecision" preference is enabled by default and defaults to 20us in Firefox 59; in 60 it will be 2ms.

  2. In Firefox, the "privacy.resistFingerprinting" preference changes the precision to 100ms or the value of "privacy.resistFingerprinting.reduceTimerPrecision.microseconds", whichever is larger.

* Partial support with prefix.

Bugs

  • Older versions of Chrome and Opera on Windows have only millisecond precision. The fractional part is always near the very start or the very end of a millisecond. (issue #158234).

  • The Spy in the Sandbox vulnerability is a class of JavaScript-based exploits that leverage the High Resolution Time API to detect CPU cache hit/miss on chosen plaintext data placed into cache by an attacker. Full security research paper is here

Resources

Data by caniuse.com
Licensed under the Creative Commons Attribution License v4.0.
https://caniuse.com/high-resolution-time