1  # mime-db
  2  
  3  [![NPM Version][npm-version-image]][npm-url]
  4  [![NPM Downloads][npm-downloads-image]][npm-url]
  5  [![Node.js Version][node-image]][node-url]
  6  [![Build Status][ci-image]][ci-url]
  7  [![Coverage Status][coveralls-image]][coveralls-url]
  8  
  9  This is a large database of mime types and information about them.
 10  It consists of a single, public JSON file and does not include any logic,
 11  allowing it to remain as un-opinionated as possible with an API.
 12  It aggregates data from the following sources:
 13  
 14  - https://www.iana.org/assignments/media-types/media-types.xhtml
 15  - https://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types
 16  - https://hg.nginx.org/nginx/raw-file/default/conf/mime.types
 17  
 18  ## Installation
 19  
 20  ```bash
 21  npm install mime-db
 22  ```
 23  
 24  ### Database Download
 25  
 26  If you intend to use this in a web browser, you can conveniently access the JSON file via [jsDelivr](https://www.jsdelivr.com/), a popular CDN (Content Delivery Network). To ensure stability and compatibility, it is advisable to specify [a release tag](https://github.com/jshttp/mime-db/tags) instead of using the 'master' branch. This is because the JSON file's format might change in future updates, and relying on a specific release tag will prevent potential issues arising from these changes.
 27  
 28  ```
 29  https://cdn.jsdelivr.net/gh/jshttp/mime-db@master/db.json
 30  ```
 31  
 32  ## Usage
 33  
 34  ```js
 35  var db = require('mime-db')
 36  
 37  // grab data on .js files
 38  var data = db['application/javascript']
 39  ```
 40  
 41  ## Data Structure
 42  
 43  The JSON file is a map lookup for lowercased mime types.
 44  Each mime type has the following properties:
 45  
 46  - `.source` - where the mime type is defined.
 47      If not set, it's probably a custom media type.
 48      - `apache` - [Apache common media types](https://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types)
 49      - `iana` - [IANA-defined media types](https://www.iana.org/assignments/media-types/media-types.xhtml)
 50      - `nginx` - [nginx media types](https://hg.nginx.org/nginx/raw-file/default/conf/mime.types)
 51  - `.extensions[]` - known extensions associated with this mime type.
 52  - `.compressible` - whether a file of this type can be gzipped.
 53  - `.charset` - the default charset associated with this type, if any.
 54  
 55  If unknown, every property could be `undefined`.
 56  
 57  ## Note on MIME Type Data and Semver
 58  
 59  This package considers the programmatic api as the semver compatibility. This means the MIME type resolution is *not* considered
 60  in the semver bumps. This means that if you want to pin your `mime-db` data you will need to do it in your application. While
 61  this expectation was not set in docs until now, it is how the pacakge operated, so we do not feel this is a breaking change.
 62  
 63  ## Contributing
 64  
 65  The primary way to contribute to this database is by updating the data in
 66  one of the upstream sources. The database is updated from the upstreams
 67  periodically and will pull in any changes.
 68  
 69  ### Registering Media Types
 70  
 71  The best way to get new media types included in this library is to register
 72  them with the IANA. The community registration procedure is outlined in
 73  [RFC 6838 section 5](https://tools.ietf.org/html/rfc6838#section-5). Types
 74  registered with the IANA are automatically pulled into this library.
 75  
 76  ### Direct Inclusion
 77  
 78  If that is not possible / feasible, they can be added directly here as a
 79  "custom" type. To do this, it is required to have a primary source that
 80  definitively lists the media type. If an extension is going to be listed as
 81  associated with this media type, the source must definitively link the
 82  media type and extension as well.
 83  
 84  To edit the database, only make PRs against `src/custom-types.json` or
 85  `src/custom-suffix.json`.
 86  
 87  The `src/custom-types.json` file is a JSON object with the MIME type as the
 88  keys and the values being an object with the following keys:
 89  
 90  - `compressible` - leave out if you don't know, otherwise `true`/`false` to
 91    indicate whether the data represented by the type is typically compressible.
 92  - `extensions` - include an array of file extensions that are associated with
 93    the type.
 94  - `notes` - human-readable notes about the type, typically what the type is.
 95  - `sources` - include an array of URLs of where the MIME type and the associated
 96    extensions are sourced from. This needs to be a [primary source](https://en.wikipedia.org/wiki/Primary_source);
 97    links to type aggregating sites and Wikipedia are _not acceptable_.
 98  
 99  To update the build, run `npm run build`.
100  
101  [ci-image]: https://badgen.net/github/checks/jshttp/mime-db/master?label=ci
102  [ci-url]: https://github.com/jshttp/mime-db/actions/workflows/ci.yml
103  [coveralls-image]: https://badgen.net/coveralls/c/github/jshttp/mime-db/master
104  [coveralls-url]: https://coveralls.io/r/jshttp/mime-db?branch=master
105  [node-image]: https://badgen.net/npm/node/mime-db
106  [node-url]: https://nodejs.org/en/download
107  [npm-downloads-image]: https://badgen.net/npm/dm/mime-db
108  [npm-url]: https://npmjs.org/package/mime-db
109  [npm-version-image]: https://badgen.net/npm/v/mime-db