Compares String.prototype.indexOf against String.prototype.includes for substring searches.
var iterations = 2000000;
var s = "hello world";s.indexOf("world") !== -1s.includes("world")s.indexOf("world") !== -1s.includes("world")s.indexOf("world") !== -1s.includes("world")| Browser | Snippet A | Snippet B | Winner |
|---|---|---|---|
1st  Safari26.5.2 | 4.00 ms | 5.00 ms | Snippet A1.25× faster |
2nd  Firefox154.0 | 6.00 ms | 7.00 ms | Snippet A1.17× faster |
3rd  Chrome152.0.7977.65 | 20.50 ms | 20.40 ms | Snippet B |
4th  Microsoft Edge152.0.4191.53 | 120.60 ms | 122.50 ms | Snippet A1.02× faster |
Median of 5 trials × 2,000,000 iterations per snippet.