The JavaScript array.toSorted() method
The toSorted() method returns a new sorted array, leaving the original untouched — the non-mutating version of sort(). [3, 1, 2].toSorted() returns [1, 2, 3] without changing the source. Like sort(), it sorts as strings by default, so pass a compare function for numbers.
Overview
toSorted() does exactly what sort() does, with one crucial difference: it returns a new sorted array instead of mutating the original. That solves the most common sort() footgun — accidentally reordering an array other code still depends on. Before toSorted(), you had to copy first ([...arr].sort()); now it's built in.
It takes the same optional compare function, with the same rules: by default it sorts elements as strings, so [10, 2, 1].toSorted() gives the surprising [1, 10, 2]. For numbers, pass (a, b) => a - b for ascending or b - a for descending — identical to sort().
It's one of a set of non-mutating array methods added recently — alongside toReversed(), toSpliced() and with() — that return copies instead of changing the array in place. These are ideal for immutable patterns like React state. Browser support is now solid across all current browsers; for older environments the copy-then-sort idiom still works.
Syntax
const sorted = array.toSorted()
const sorted = array.toSorted(compareFn)
[3, 1, 2].toSorted() // [1, 2, 3], original unchanged
[10, 2, 1].toSorted((a, b) => a - b) // [1, 2, 10]Parameters
The array.toSorted() method accepts the following parameters.
| Parameter | Description |
|---|---|
compareFn |
Optional. Function comparing two elements (a, b) — negative to put a first, positive to put b first. Omit it and elements sort as strings. |
Example
<pre id="out" style="font:15px ui-monospace,monospace"></pre>
<script>
const scores = [42, 8, 100, 16];
const sorted = scores.toSorted((a, b) => a - b);
document.getElementById('out').textContent =
'sorted: ' + sorted.join(', ') + '\n' +
'original: ' + scores.join(', '); // original unchanged
</script>Best practices
- Use
toSorted()when you need a sorted copy and must keep the original order. - Pass a compare function for numbers —
(a, b) => a - b— or the default string sort mis-orders them. - Prefer it over
[...arr].sort()in modern code; it states the non-mutating intent. - Use the mutating sort() only when changing the array in place is what you want.
Frequently asked questions
What is the difference between toSorted() and sort()?
toSorted() returns a new sorted array and leaves the original alone; sort() sorts the array in place (mutating it).Does toSorted() sort numbers correctly?
arr.toSorted((a, b) => a - b) for numbers.Is toSorted() supported in all browsers?
[...arr].sort() instead.