Date.now vs new Date().getTime() vs +new Date

JavaScript performance comparison

Revision 11 of this test case created by Jamie Pate

Preparation code

<script>
if (!('now' in Date)) {
 Date.now = function() { return new Date().getTime();}
}
Date.now2 = function() { return +(new Date);}
</script>

Test runner

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Testing in unknown unknown
Test Ops/sec
Date.now()
Date.now()
pending…
new Date().getTime()
new Date().getTime()
pending…
+new Date
+new Date
pending…
parentheses 1
(new Date).getTime()
pending…
parentheses 2
(new Date()).getTime()
pending…
valueof
new Date().valueOf()
pending…
+(new Date) shim
Date.now2();
pending…

Compare results of other browsers

Revisions

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1 comment

vsync commented :

The results are drastically different between FF 32 and Chrome 38. FF outperforms Chrome in the fastest case, which is "Date.now()".

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