5.0 KiB
Mime
A comprehensive, compact MIME type module.
Install
NPM
npm install mime
Browser
It is recommended that you use a bundler such as webpack or browserify to package your code. However, browser-ready versions are available via skypack.dev as follows:
// Full version
<script type="module">
import mime from "https://cdn.skypack.dev/mime";
</script>
// "lite" version
<script type="module">
import mime from "https://cdn.skypack.dev/mime/lite";
</script>
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
The "lite" version of this module 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');
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:
- Intelligently resolved type conflicts (See mime-score for details)
- 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.
Note: Inputs to this API are case-insensitive. Outputs (returned values) will be lowercase.
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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