startsWith performance

String.prototype.startsWith performance

Shazzer Master

Created Jul 4, 2026

Updated Jul 4, 2026

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CategoryJavaScript Syntax

VisibilityPublic

TypePERF

CharsetUTF-8

Code used before fuzz:

var iterations = 2000000;0x0D
var s = "hello world";

Snippet A:

s.startsWith("hello")

Sample payloads

s.startsWith("hello")

Snippet

s.startsWith("hello")

Median of 5 trials × 2,000,000 iterations.