Mime
A comprehensive, compact MIME type module.
Version 2 Notes
Version 2 is a breaking change from 1.x, as the semver implies. Specifically:
- ES6 support required (node@>=6)
lookup()
renamed togetType()
extension()
renamed togetExtension()
charset()
andload()
methods have been removed
If you prefer the legacy version of this module please npm install mime@^1
. Version 1 docs may be found here.
Install - NPM
npm install mime
Quick Start
For the full version (800+ MIME types, 1,000+ extensions):
const mime = require('mime');
mime.getType('txt'); // ⇨ 'text/plain'
mime.getExtension('text/plain'); // ⇨ 'txt'
See Mime API below for API details.
Lite Version
There is also a "lite" version of this module that omits vendor-specific
(*/vnd.*
) and experimental (*/x-*
) types. It weighs in at ~2.5KB, compared
to 8KB for the full version. To load the lite version:
const mime = require('mime/lite');
Browser-ready Versions
To use this module in the browser, you would typlically use webpack or browserify to package your code. However, browser-ready versions are available via wzrd.in. E.g. For the full version:
<script src="https://wzrd.in/standalone/mime@latest"></script>
<script>
mime.getType(...); // etc.
<script>
Or, for the mime/lite
version:
<script src="https://wzrd.in/standalone/mime%2flite@latest"></script>
<script>
mimelite.getType(...); // (Note `mimelite` here)
<script>
Mime .vs. mime-types .vs. mime-db modules
For those of you wondering about the difference between these [popular] NPM modules, here's a brief rundown ...
mime-db
is "the source of
truth" for MIME type information. It is not an API. Rather, it is a canonical
dataset of mime type definitions pulled from IANA, Apache, NGINX, and custom mappings
submitted by the Node.js community.
mime-types
is a thin
wrapper around mime-db that provides an API drop-in compatible(ish) with mime @ < v1.3.6
API.
mime
is, as of v2, a self-contained module bundled with a pre-optimized version
of the mime-db
dataset. It provides a simplified API with the following characteristics:
- Internally consistent type ⇔ extension mapping. I.e.
mime.getType(mime.getExtension(type)) == type
will always be true - Method naming consistent with industry best-practices
- Compact footprint. E.g. The minified+compressed sizes of the various modules:
Module | Size |
---|---|
mime-db |
18 KB |
mime-types |
same as mime-db |
mime |
8 KB |
mime/lite |
2 KB |
Mime API
Both require('mime')
and require('mime/lite')
return instances of the MIME
class, documented below.
new Mime(typeMap, ... more maps)
Most users of this module will not need to create Mime instances directly. However if you would like to create custom mappings, you may do so as follows ...
// Require Mime class
const Mime = require('mime/Mime');
// Define mime type -> extensions map
const typeMap = {
'text/abc': ['abc', 'alpha', 'bet'],
'text/def': ['leppard']
};
// Create and use Mime instance
const myMime = new Mime(typeMap);
myMime.getType('abc'); // ⇨ 'text/abc'
myMime.getExtension('text/def'); // ⇨ 'leppard'
If more than one map argument is provided, each map is define()
ed (see below), in order.
mime.getType(pathOrExtension)
Get mime type for the given path or extension. E.g.
mime.getType('js'); // ⇨ 'application/javascript'
mime.getType('json'); // ⇨ 'application/json'
mime.getType('txt'); // ⇨ 'text/plain'
mime.getType('dir/text.txt'); // ⇨ 'text/plain'
mime.getType('dir\\text.txt'); // ⇨ 'text/plain'
mime.getType('.text.txt'); // ⇨ 'text/plain'
mime.getType('.txt'); // ⇨ 'text/plain'
null
is returned in cases where an extension is not detected or recognized
mime.getType('foo/txt'); // ⇨ null
mime.getType('bogus_type'); // ⇨ null
mime.getExtension(type)
Get extension for the given mime type. Charset options (often included in Content-Type headers) are ignored.
mime.getExtension('text/plain'); // ⇨ 'txt'
mime.getExtension('application/json'); // ⇨ 'json'
mime.getExtension('text/html; charset=utf8'); // ⇨ 'html'
mime.define(typeMap[, force = false])
Define [more] type mappings.
typeMap
is a map of type -> extensions, as documented in new Mime
, above.
By default this method will throw an error if you try to map a type to an
extension that is already assigned to another type. Passing true
for the
force
argument will suppress this behavior (overriding any previous mapping).
mime.define({'text/x-abc': ['abc', 'abcd']});
mime.getType('abcd'); // ⇨ 'text/x-abc'
mime.getExtension('text/x-abc') // ⇨ 'abc'
Command Line
mime [path_or_extension]
E.g.
> mime scripts/jquery.js
application/javascript
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