Array copyWithin()Baseline · Widely available
The copyWithin() method of arrays and typed arrays shifts or copies items of an array to another index of the array without changing its length.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Sep 20, 2016. Widely available since Mar 20, 2019.
Browser support
DesktopChrome
1–44Not supported
45+Supportedsince Sep 1, 2015
Current: 155Edge
12+Supportedsince Jul 29, 2015
Current: 154Firefox
1–33Not supported
34+Supportedsince Dec 1, 2014
Current: 157Safari
1–9.1Not supported
10+Supportedsince Sep 20, 2016
Current: 27MobileChrome Android
18–44Not supported
45+Supportedsince Sep 1, 2015
Current: 155Firefox Android
4–33Not supported
34+Supportedsince Dec 1, 2014
Current: 157Safari iOS
1–9.3Not supported
10+Supportedsince Sep 13, 2016
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
Full syntax and examples are on MDN: copyWithin.
Feature detection
JS · check before using
if ("copyWithin" in Array || ("prototype" in Array && "copyWithin" in Array.prototype)) {
// Array.copyWithin is available
}Documentation (MDN)
Specification
Sub-features
Support for each part of the feature (2). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| Array.copyWithin | 45 | 12 | 32 | 9 | 45 | 32 | 9 |
| TypedArray.copyWithin | 45 | 12 | 34 | 10 | 45 | 34 | 10 |