# query-string [](https://travis-ci.org/sindresorhus/query-string) > Parse and stringify URL [query strings](https://en.wikipedia.org/wiki/Query_string) ## Install ``` $ npm install query-string ``` This module targets Node.js 6 or later and the latest version of Chrome, Firefox, and Safari. If you want support for older browsers, or, [if your project is using create-react-app v1](https://github.com/sindresorhus/query-string/pull/148#issuecomment-399656020), use version 5: `npm install query-string@5`. ## Usage ```js const queryString = require('query-string'); console.log(location.search); //=> '?foo=bar' const parsed = queryString.parse(location.search); console.log(parsed); //=> {foo: 'bar'} console.log(location.hash); //=> '#token=bada55cafe' const parsedHash = queryString.parse(location.hash); console.log(parsedHash); //=> {token: 'bada55cafe'} parsed.foo = 'unicorn'; parsed.ilike = 'pizza'; const stringified = queryString.stringify(parsed); //=> 'foo=unicorn&ilike=pizza' location.search = stringified; // note that `location.search` automatically prepends a question mark console.log(location.search); //=> '?foo=unicorn&ilike=pizza' ``` ## API ### .parse(string, options?) Parse a query string into an object. Leading `?` or `#` are ignored, so you can pass `location.search` or `location.hash` directly. The returned object is created with [`Object.create(null)`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/create) and thus does not have a `prototype`. #### options Type: `object` ##### decode Type: `boolean`<br> Default: `true` Decode the keys and values. URL components are decoded with [`decode-uri-component`](https://github.com/SamVerschueren/decode-uri-component). ##### arrayFormat Type: `string`<br> Default: `'none'` - `'bracket'`: Parse arrays with bracket representation: ```js queryString.parse('foo[]=1&foo[]=2&foo[]=3', {arrayFormat: 'bracket'}); //=> {foo: ['1', '2', '3']} ``` - `'index'`: Parse arrays with index representation: ```js queryString.parse('foo[0]=1&foo[1]=2&foo[3]=3', {arrayFormat: 'index'}); //=> {foo: ['1', '2', '3']} ``` - `'comma'`: Parse arrays with elements separated by comma: ```js queryString.parse('foo=1,2,3', {arrayFormat: 'comma'}); //=> {foo: ['1', '2', '3']} ``` - `'none'`: Parse arrays with elements using duplicate keys: ```js queryString.parse('foo=1&foo=2&foo=3'); //=> {foo: ['1', '2', '3']} ``` ##### sort Type: `Function | boolean`<br> Default: `true` Supports both `Function` as a custom sorting function or `false` to disable sorting. ##### parseNumbers Type: `boolean`<br> Default: `false` ```js queryString.parse('foo=1', {parseNumbers: true}); //=> {foo: 1} ``` Parse the value as a number type instead of string type if it's a number. ##### parseBooleans Type: `boolean`<br> Default: `false` ```js queryString.parse('foo=true', {parseBooleans: true}); //=> {foo: true} ``` Parse the value as a boolean type instead of string type if it's a boolean. ### .stringify(object, [options]) Stringify an object into a query string and sorting the keys. #### options Type: `object` ##### strict Type: `boolean`<br> Default: `true` Strictly encode URI components with [strict-uri-encode](https://github.com/kevva/strict-uri-encode). It uses [encodeURIComponent](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent) if set to false. You probably [don't care](https://github.com/sindresorhus/query-string/issues/42) about this option. ##### encode Type: `boolean`<br> Default: `true` [URL encode](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent) the keys and values. ##### arrayFormat Type: `string`<br> Default: `'none'` - `'bracket'`: Serialize arrays using bracket representation: ```js queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'bracket'}); //=> 'foo[]=1&foo[]=2&foo[]=3' ``` - `'index'`: Serialize arrays using index representation: ```js queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'index'}); //=> 'foo[0]=1&foo[1]=2&foo[2]=3' ``` - `'comma'`: Serialize arrays by separating elements with comma: ```js queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'comma'}); //=> 'foo=1,2,3' ``` - `'none'`: Serialize arrays by using duplicate keys: ```js queryString.stringify({foo: [1, 2, 3]}); //=> 'foo=1&foo=2&foo=3' ``` ##### sort Type: `Function | boolean` Supports both `Function` as a custom sorting function or `false` to disable sorting. ```js const order = ['c', 'a', 'b']; queryString.stringify({a: 1, b: 2, c: 3}, { sort: (a, b) => order.indexOf(a) - order.indexOf(b) }); //=> 'c=3&a=1&b=2' ``` ```js queryString.stringify({b: 1, c: 2, a: 3}, {sort: false}); //=> 'b=1&c=2&a=3' ``` If omitted, keys are sorted using `Array#sort()`, which means, converting them to strings and comparing strings in Unicode code point order. ### .extract(string) Extract a query string from a URL that can be passed into `.parse()`. ### .parseUrl(string, options?) Extract the URL and the query string as an object. The `options` are the same as for `.parse()`. Returns an object with a `url` and `query` property. ```js queryString.parseUrl('https://foo.bar?foo=bar'); //=> {url: 'https://foo.bar', query: {foo: 'bar'}} ``` ## Nesting This module intentionally doesn't support nesting as it's not spec'd and varies between implementations, which causes a lot of [edge cases](https://github.com/visionmedia/node-querystring/issues). You're much better off just converting the object to a JSON string: ```js queryString.stringify({ foo: 'bar', nested: JSON.stringify({ unicorn: 'cake' }) }); //=> 'foo=bar&nested=%7B%22unicorn%22%3A%22cake%22%7D' ``` However, there is support for multiple instances of the same key: ```js queryString.parse('likes=cake&name=bob&likes=icecream'); //=> {likes: ['cake', 'icecream'], name: 'bob'} queryString.stringify({color: ['taupe', 'chartreuse'], id: '515'}); //=> 'color=taupe&color=chartreuse&id=515' ``` ## Falsy values Sometimes you want to unset a key, or maybe just make it present without assigning a value to it. Here is how falsy values are stringified: ```js queryString.stringify({foo: false}); //=> 'foo=false' queryString.stringify({foo: null}); //=> 'foo' queryString.stringify({foo: undefined}); //=> '' ``` --- <div align="center"> <b> <a href="https://tidelift.com/subscription/pkg/npm-query-string?utm_source=npm-query-string&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a> </b> <br> _{Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.} </div>