|  |  |  |  | # JSON5 – JSON for Humans
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							|  |  |  |  | [][Build | 
					
						
							|  |  |  |  | Status] [][Coverage | 
					
						
							|  |  |  |  | Status] | 
					
						
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							|  |  |  |  | JSON5 is an extension to the popular [JSON] file format that aims to be | 
					
						
							|  |  |  |  | easier to **write and maintain _by hand_ (e.g. for config files)**. | 
					
						
							|  |  |  |  | It is _not intended_ to be used for machine-to-machine communication. | 
					
						
							|  |  |  |  | (Keep using JSON or other file formats for that. 🙂) | 
					
						
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							|  |  |  |  | JSON5 was started in 2012, and as of 2022, now gets **[>65M downloads/week](https://www.npmjs.com/package/json5)**, | 
					
						
							|  |  |  |  | ranks in the **[top 0.1%](https://gist.github.com/anvaka/8e8fa57c7ee1350e3491)** of the most depended-upon packages on npm, | 
					
						
							|  |  |  |  | and has been adopted by major projects like | 
					
						
							|  |  |  |  | **[Chromium](https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/runtime_enabled_features.json5;drc=5de823b36e68fd99009a29281b17bc3a1d6b329c), | 
					
						
							|  |  |  |  | [Next.js](https://github.com/vercel/next.js/blob/b88f20c90bf4659b8ad5cb2a27956005eac2c7e8/packages/next/lib/find-config.ts#L43-L46), | 
					
						
							|  |  |  |  | [Babel](https://babeljs.io/docs/en/config-files#supported-file-extensions), | 
					
						
							|  |  |  |  | [Retool](https://community.retool.com/t/i-am-attempting-to-append-several-text-fields-to-a-google-sheet-but-receiving-a-json5-invalid-character-error/7626), | 
					
						
							|  |  |  |  | [WebStorm](https://www.jetbrains.com/help/webstorm/json.html), | 
					
						
							|  |  |  |  | and [more](https://github.com/json5/json5/wiki/In-the-Wild)**. | 
					
						
							|  |  |  |  | It's also natively supported on **[Apple platforms](https://developer.apple.com/documentation/foundation/jsondecoder/3766916-allowsjson5)** | 
					
						
							|  |  |  |  | like **MacOS** and **iOS**. | 
					
						
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							|  |  |  |  | Formally, the **[JSON5 Data Interchange Format](https://spec.json5.org/)** is a superset of JSON | 
					
						
							|  |  |  |  | (so valid JSON files will always be valid JSON5 files) | 
					
						
							|  |  |  |  | that expands its syntax to include some productions from [ECMAScript 5.1] (ES5). | 
					
						
							|  |  |  |  | It's also a strict _subset_ of ES5, so valid JSON5 files will always be valid ES5. | 
					
						
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							|  |  |  |  | This JavaScript library is a reference implementation for JSON5 parsing and serialization, | 
					
						
							|  |  |  |  | and is directly used in many of the popular projects mentioned above | 
					
						
							|  |  |  |  | (where e.g. extreme performance isn't necessary), | 
					
						
							|  |  |  |  | but others have created [many other libraries](https://github.com/json5/json5/wiki/In-the-Wild) | 
					
						
							|  |  |  |  | across many other platforms. | 
					
						
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							|  |  |  |  | [Build Status]: https://app.travis-ci.com/json5/json5 | 
					
						
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							|  |  |  |  | [Coverage Status]: https://coveralls.io/github/json5/json5 | 
					
						
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							|  |  |  |  | [JSON]: https://tools.ietf.org/html/rfc7159 | 
					
						
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							|  |  |  |  | [ECMAScript 5.1]: https://www.ecma-international.org/ecma-262/5.1/ | 
					
						
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							|  |  |  |  | ## Summary of Features
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							|  |  |  |  | The following ECMAScript 5.1 features, which are not supported in JSON, have | 
					
						
							|  |  |  |  | been extended to JSON5. | 
					
						
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							|  |  |  |  | ### Objects
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							|  |  |  |  | - Object keys may be an ECMAScript 5.1 _[IdentifierName]_. | 
					
						
							|  |  |  |  | - Objects may have a single trailing comma. | 
					
						
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							|  |  |  |  | ### Arrays
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							|  |  |  |  | - Arrays may have a single trailing comma. | 
					
						
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							|  |  |  |  | ### Strings
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							|  |  |  |  | - Strings may be single quoted. | 
					
						
							|  |  |  |  | - Strings may span multiple lines by escaping new line characters. | 
					
						
							|  |  |  |  | - Strings may include character escapes. | 
					
						
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							|  |  |  |  | ### Numbers
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							|  |  |  |  | - Numbers may be hexadecimal. | 
					
						
							|  |  |  |  | - Numbers may have a leading or trailing decimal point. | 
					
						
							|  |  |  |  | - Numbers may be [IEEE 754] positive infinity, negative infinity, and NaN. | 
					
						
							|  |  |  |  | - Numbers may begin with an explicit plus sign. | 
					
						
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							|  |  |  |  | ### Comments
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							|  |  |  |  | - Single and multi-line comments are allowed. | 
					
						
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							|  |  |  |  | ### White Space
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							|  |  |  |  | - Additional white space characters are allowed. | 
					
						
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							|  |  |  |  | [IdentifierName]: https://www.ecma-international.org/ecma-262/5.1/#sec-7.6 | 
					
						
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							|  |  |  |  | [IEEE 754]: http://ieeexplore.ieee.org/servlet/opac?punumber=4610933 | 
					
						
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							|  |  |  |  | ## Example
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							|  |  |  |  | Kitchen-sink example: | 
					
						
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | { | 
					
						
							|  |  |  |  |   // comments | 
					
						
							|  |  |  |  |   unquoted: 'and you can quote me on that', | 
					
						
							|  |  |  |  |   singleQuotes: 'I can use "double quotes" here', | 
					
						
							|  |  |  |  |   lineBreaks: "Look, Mom! \ | 
					
						
							|  |  |  |  | No \\n's!", | 
					
						
							|  |  |  |  |   hexadecimal: 0xdecaf, | 
					
						
							|  |  |  |  |   leadingDecimalPoint: .8675309, andTrailing: 8675309., | 
					
						
							|  |  |  |  |   positiveSign: +1, | 
					
						
							|  |  |  |  |   trailingComma: 'in objects', andIn: ['arrays',], | 
					
						
							|  |  |  |  |   "backwardsCompatible": "with JSON", | 
					
						
							|  |  |  |  | } | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | A more real-world example is [this config file](https://github.com/chromium/chromium/blob/feb3c9f670515edf9a88f185301cbd7794ee3e52/third_party/blink/renderer/platform/runtime_enabled_features.json5) | 
					
						
							|  |  |  |  | from the Chromium/Blink project. | 
					
						
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							|  |  |  |  | ## Specification
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							|  |  |  |  | For a detailed explanation of the JSON5 format, please read the [official | 
					
						
							|  |  |  |  | specification](https://json5.github.io/json5-spec/). | 
					
						
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							|  |  |  |  | ## Installation and Usage
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							|  |  |  |  | ### Node.js
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							|  |  |  |  | ```sh | 
					
						
							|  |  |  |  | npm install json5 | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | #### CommonJS
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | const JSON5 = require('json5') | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | #### Modules
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | import JSON5 from 'json5' | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | ### Browsers
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							|  |  |  |  | #### UMD
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							|  |  |  |  | ```html | 
					
						
							|  |  |  |  | <!-- This will create a global `JSON5` variable. --> | 
					
						
							|  |  |  |  | <script src="https://unpkg.com/json5@2/dist/index.min.js"></script> | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | #### Modules
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							|  |  |  |  | ```html | 
					
						
							|  |  |  |  | <script type="module"> | 
					
						
							|  |  |  |  |   import JSON5 from 'https://unpkg.com/json5@2/dist/index.min.mjs' | 
					
						
							|  |  |  |  | </script> | 
					
						
							|  |  |  |  | ``` | 
					
						
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							|  |  |  |  | ## API
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							|  |  |  |  | The JSON5 API is compatible with the [JSON API]. | 
					
						
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							|  |  |  |  | [JSON API]: | 
					
						
							|  |  |  |  | https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON | 
					
						
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							|  |  |  |  | ### JSON5.parse()
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							|  |  |  |  | Parses a JSON5 string, constructing the JavaScript value or object described by | 
					
						
							|  |  |  |  | the string. An optional reviver function can be provided to perform a | 
					
						
							|  |  |  |  | transformation on the resulting object before it is returned. | 
					
						
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							|  |  |  |  | #### Syntax
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							|  |  |  |  |     JSON5.parse(text[, reviver]) | 
					
						
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							|  |  |  |  | #### Parameters
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							|  |  |  |  | - `text`: The string to parse as JSON5. | 
					
						
							|  |  |  |  | - `reviver`: If a function, this prescribes how the value originally produced by | 
					
						
							|  |  |  |  |   parsing is transformed, before being returned. | 
					
						
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							|  |  |  |  | #### Return value
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							|  |  |  |  | The object corresponding to the given JSON5 text. | 
					
						
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							|  |  |  |  | ### JSON5.stringify()
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							|  |  |  |  | Converts a JavaScript value to a JSON5 string, optionally replacing values if a | 
					
						
							|  |  |  |  | replacer function is specified, or optionally including only the specified | 
					
						
							|  |  |  |  | properties if a replacer array is specified. | 
					
						
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							|  |  |  |  | #### Syntax
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							|  |  |  |  |     JSON5.stringify(value[, replacer[, space]]) | 
					
						
							|  |  |  |  |     JSON5.stringify(value[, options]) | 
					
						
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							|  |  |  |  | #### Parameters
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							|  |  |  |  | - `value`: The value to convert to a JSON5 string. | 
					
						
							|  |  |  |  | - `replacer`: A function that alters the behavior of the stringification | 
					
						
							|  |  |  |  |   process, or an array of String and Number objects that serve as a whitelist | 
					
						
							|  |  |  |  |   for selecting/filtering the properties of the value object to be included in | 
					
						
							|  |  |  |  |   the JSON5 string. If this value is null or not provided, all properties of the | 
					
						
							|  |  |  |  |   object are included in the resulting JSON5 string. | 
					
						
							|  |  |  |  | - `space`: A String or Number object that's used to insert white space into the | 
					
						
							|  |  |  |  |   output JSON5 string for readability purposes. If this is a Number, it | 
					
						
							|  |  |  |  |   indicates the number of space characters to use as white space; this number is | 
					
						
							|  |  |  |  |   capped at 10 (if it is greater, the value is just 10). Values less than 1 | 
					
						
							|  |  |  |  |   indicate that no space should be used. If this is a String, the string (or the | 
					
						
							|  |  |  |  |   first 10 characters of the string, if it's longer than that) is used as white | 
					
						
							|  |  |  |  |   space. If this parameter is not provided (or is null), no white space is used. | 
					
						
							|  |  |  |  |   If white space is used, trailing commas will be used in objects and arrays. | 
					
						
							|  |  |  |  | - `options`: An object with the following properties: | 
					
						
							|  |  |  |  |   - `replacer`: Same as the `replacer` parameter. | 
					
						
							|  |  |  |  |   - `space`: Same as the `space` parameter. | 
					
						
							|  |  |  |  |   - `quote`: A String representing the quote character to use when serializing | 
					
						
							|  |  |  |  |     strings. | 
					
						
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							|  |  |  |  | #### Return value
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							|  |  |  |  | A JSON5 string representing the value. | 
					
						
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							|  |  |  |  | ### Node.js `require()` JSON5 files
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							|  |  |  |  | When using Node.js, you can `require()` JSON5 files by adding the following | 
					
						
							|  |  |  |  | statement. | 
					
						
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | require('json5/lib/register') | 
					
						
							|  |  |  |  | ``` | 
					
						
							|  |  |  |  | 
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							|  |  |  |  | Then you can load a JSON5 file with a Node.js `require()` statement. For | 
					
						
							|  |  |  |  | example: | 
					
						
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							|  |  |  |  | ```js | 
					
						
							|  |  |  |  | const config = require('./config.json5') | 
					
						
							|  |  |  |  | ``` | 
					
						
							|  |  |  |  | 
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							|  |  |  |  | ## CLI
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							|  |  |  |  | Since JSON is more widely used than JSON5, this package includes a CLI for | 
					
						
							|  |  |  |  | converting JSON5 to JSON and for validating the syntax of JSON5 documents. | 
					
						
							|  |  |  |  | 
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							|  |  |  |  | ### Installation
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							|  |  |  |  | ```sh | 
					
						
							|  |  |  |  | npm install --global json5 | 
					
						
							|  |  |  |  | ``` | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | ### Usage
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							|  |  |  |  | ```sh | 
					
						
							|  |  |  |  | json5 [options] <file> | 
					
						
							|  |  |  |  | ``` | 
					
						
							|  |  |  |  | 
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							|  |  |  |  | If `<file>` is not provided, then STDIN is used. | 
					
						
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							|  |  |  |  | #### Options:
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							|  |  |  |  | - `-s`, `--space`: The number of spaces to indent or `t` for tabs | 
					
						
							|  |  |  |  | - `-o`, `--out-file [file]`: Output to the specified file, otherwise STDOUT | 
					
						
							|  |  |  |  | - `-v`, `--validate`: Validate JSON5 but do not output JSON | 
					
						
							|  |  |  |  | - `-V`, `--version`: Output the version number | 
					
						
							|  |  |  |  | - `-h`, `--help`: Output usage information | 
					
						
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							|  |  |  |  | ## Contributing
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							|  |  |  |  | ### Development
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							|  |  |  |  | ```sh | 
					
						
							|  |  |  |  | git clone https://github.com/json5/json5 | 
					
						
							|  |  |  |  | cd json5 | 
					
						
							|  |  |  |  | npm install | 
					
						
							|  |  |  |  | ``` | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | When contributing code, please write relevant tests and run `npm test` and `npm | 
					
						
							|  |  |  |  | run lint` before submitting pull requests. Please use an editor that supports | 
					
						
							|  |  |  |  | [EditorConfig](http://editorconfig.org/). | 
					
						
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 | 
					
						
							|  |  |  |  | ### Issues
 | 
					
						
							|  |  |  |  | To report bugs or request features regarding the JSON5 **data format**, | 
					
						
							|  |  |  |  | please submit an issue to the official | 
					
						
							|  |  |  |  | **[_specification_ repository](https://github.com/json5/json5-spec)**. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | Note that we will never add any features that make JSON5 incompatible with ES5; | 
					
						
							|  |  |  |  | that compatibility is a fundamental premise of JSON5. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | To report bugs or request features regarding this **JavaScript implementation** | 
					
						
							|  |  |  |  | of JSON5, please submit an issue to **_this_ repository**. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | ## License
 | 
					
						
							|  |  |  |  | MIT. See [LICENSE.md](./LICENSE.md) for details. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | ## Credits
 | 
					
						
							|  |  |  |  | [Aseem Kishore](https://github.com/aseemk) founded this project. | 
					
						
							|  |  |  |  | He wrote a [blog post](https://aseemk.substack.com/p/ignore-the-f-ing-haters-json5) | 
					
						
							|  |  |  |  | about the journey and lessons learned 10 years in. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [Michael Bolin](http://bolinfest.com/) independently arrived at and published | 
					
						
							|  |  |  |  | some of these same ideas with awesome explanations and detail. Recommended | 
					
						
							|  |  |  |  | reading: [Suggested Improvements to JSON](http://bolinfest.com/essays/json.html) | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [Douglas Crockford](http://www.crockford.com/) of course designed and built | 
					
						
							|  |  |  |  | JSON, but his state machine diagrams on the [JSON website](http://json.org/), as | 
					
						
							|  |  |  |  | cheesy as it may sound, gave us motivation and confidence that building a new | 
					
						
							|  |  |  |  | parser to implement these ideas was within reach! The original | 
					
						
							|  |  |  |  | implementation of JSON5 was also modeled directly off of Doug’s open-source | 
					
						
							|  |  |  |  | [json_parse.js] parser. We’re grateful for that clean and well-documented | 
					
						
							|  |  |  |  | code. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [json_parse.js]: | 
					
						
							|  |  |  |  | https://github.com/douglascrockford/JSON-js/blob/03157639c7a7cddd2e9f032537f346f1a87c0f6d/json_parse.js | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [Max Nanasy](https://github.com/MaxNanasy) has been an early and prolific | 
					
						
							|  |  |  |  | supporter, contributing multiple patches and ideas. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [Andrew Eisenberg](https://github.com/aeisenberg) contributed the original | 
					
						
							|  |  |  |  | `stringify` method. | 
					
						
							|  |  |  |  | 
 | 
					
						
							|  |  |  |  | [Jordan Tucker](https://github.com/jordanbtucker) has aligned JSON5 more closely | 
					
						
							|  |  |  |  | with ES5, wrote the official JSON5 specification, completely rewrote the | 
					
						
							|  |  |  |  | codebase from the ground up, and is actively maintaining this project. |