# The String split() method

> Learn how the JavaScript split() method breaks a string into an array of tokens every time it finds a separator pattern, with the case-sensitive match removed.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2019-03-01 | Updated: 2026-09-20 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/javascript-string-split/

`split()` breaks a string into an array of tokens every time it finds the separator you pass to it. The match is case sensitive, and the separator itself is removed from the result:

```js
const phrase = 'I love my dog! Dogs are great'
const tokens = phrase.split('dog')

tokens //["I love my ", "! Dogs are great"]
```

Notice that `Dogs` did not match, because the separator was lowercase `dog`.

You reach for `split()` any time you have one string that contains several pieces of data. A comma-separated line is the classic case:

```js
const csv = 'Flavio,38,Milan'
csv.split(',') //['Flavio', '38', 'Milan']
```

Or a sentence you want to break into words:

```js
'the quick brown fox'.split(' ') //['the', 'quick', 'brown', 'fox']
```

## What happens with edge cases?

If the separator is not found, you get an array with the whole string as its only item:

```js
'hello'.split(',') //['hello']
```

If you call `split()` with no argument at all, you get the same thing: the entire string wrapped in an array.

An empty string as separator splits the string into individual characters:

```js
'ciao'.split('') //['c', 'i', 'a', 'o']
```

## Limiting the number of results

`split()` accepts a second argument, the maximum number of tokens to return:

```js
'one,two,three,four'.split(',', 2) //['one', 'two']
```

Everything after the limit is discarded, not merged into the last token.

## Splitting with a regular expression

The separator can also be a regular expression. This is handy when the input is messy, for example when words are separated by a variable number of spaces:

```js
'apples   and    oranges'.split(/\s+/) //['apples', 'and', 'oranges']
```

## Be careful with emojis

Splitting by the empty string works character by character, but JavaScript strings are sequences of UTF-16 code units (see also [Unicode](https://flaviocopes.com/unicode/)). Characters outside the basic range, like most emojis, take two code units, and `split('')` breaks them apart:

```js
'hi🐶'.split('') //['h', 'i', '\uD83D', '\uDC36']
```

Spreading the string (or `Array.from(str)`) iterates by Unicode code points, so a single-code-point emoji stays intact:

```js
[...'hi🐶'] //['h', 'i', '🐶']
Array.from('hi🐶') //['h', 'i', '🐶']
```

That is still not enough for every emoji. Some characters you see as one symbol are several code points joined together: family emoji built with ZWJ sequences, flags, skin tones. Spread splits those. To split by what a person sees as one character (a grapheme cluster), use `Intl.Segmenter` (Baseline 2024):

```js
const text = 'hi👨‍👩‍👧'
const segmenter = new Intl.Segmenter('en', { granularity: 'grapheme' })
const chars = [...segmenter.segment(text)].map(s => s.segment)

chars //['h', 'i', '👨‍👩‍👧']
```

For words instead of characters, use `{ granularity: 'word' }` and filter with `isWordLike`. See [how to cut a string into words](https://flaviocopes.com/how-to-cut-string-words-javascript/).

One last tip: `split()` and `join()` are natural companions. Split a string into an array, transform the items, then `join()` them back into a string.