https://github.com/somajitdey/mime-db-lite
A tiny, lightweight JavaScript API to query mime-db (Media-type / MIME-type database)
https://github.com/somajitdey/mime-db-lite
Last synced: 2 months ago
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A tiny, lightweight JavaScript API to query mime-db (Media-type / MIME-type database)
- Host: GitHub
- URL: https://github.com/somajitdey/mime-db-lite
- Owner: SomajitDey
- License: mit
- Created: 2025-05-21T06:08:04.000Z (5 months ago)
- Default Branch: main
- Last Pushed: 2025-06-09T17:32:51.000Z (4 months ago)
- Last Synced: 2025-06-23T19:42:06.196Z (3 months ago)
- Language: JavaScript
- Homepage:
- Size: 165 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# mime-db-lite
[](https://www.npmjs.com/package/mime-db-lite)
[](https://github.com/SomajitDey/mime-db-lite/actions/workflows/test.yaml)
[](https://github.com/SomajitDey/mime-db-lite/actions/workflows/publish.yaml)
A tiny, lightweight, portable [JavaScript module](./index.js) to query the complete [mime-db](https://github.com/jshttp/mime-db) (a popular Media-type / MIME-type / Content-type database). Data is actually sourced from [mime-db-cdn](https://github.com/SomajitDey/mime-db-cdn), which mirrors [mime-db](https://github.com/jshttp/mime-db) with added features.
🚀 Consumes less run-time memory by fetching data as and when needed, with optional caching. Ideal for low footprint applications.
🚀 Cross-platform: Runs on browsers, server-side (e.g. NodeJS) or serverless (e.g. Cloudflare Workers V8 isolates).
🚀 Standard: [ESM](https://nodejs.org/api/esm.html#modules-ecmascript-modules).
🚀 [Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_promises)-based; exports `async` methods.
🚀 Accepts custom [`fetch()`](https://www.w3schools.com/jsref/api_fetch.asp) method, if any.
## Install and `import`
For browsers:
```html
import DB from 'https://cdn.jsdelivr.net/npm/mime-db-lite@2.1.1/index.min.js';
// Above, replace 2.1.1 with the actual version you'd be using, or use 'latest'
// Your code here ...
```
For Node.js:
Install as
```bash
npm install mime-db-lite
```
Import as
```javascript
import DB from 'mime-db-lite';
```
## Instantiation, custom `fetch()` and LRU cache
Create an instance of the [imported DB class](#install-andor-import) to use the [fetch() API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) provided by the runtime and forgo caching.
👉 For browsers, the native `fetch()` will still use the [HTTP-cache](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Caching).
```javascript
const db = new DB();
```
To use an in-memory cache, instantiate as:
```javascript
const db = new DB({ cacheMaxEntries: });
```
`` denotes the maximum number of entries the cache can store, beyond which the [LRU](## "Least Recently Used") entries will be evicted to make just enough space.
👉 Using an LRU cache claims more run-time memory in return for faster lookups. For browsers this may be unnecessary, because browser-native `fetch()` already uses HTTP-cache by default.
To use a custom `fetch()` method, e.g. `async function custFetch (url) { ... }`, instantiate as:
```javascript
const db = new DB({ fetch: custFetch });
```
or, use an arrow function
```javascript
const db = new DB({
fetch: async (url) => {
// Your code here
}
});
```
## API
### `db.mimeToExtensions(mimeType)` or its alias `db.getExtensions(mimeType)`
Returns a promise that fulfills with an array of file-extensions.
`mimeType`
String representing a MIME-type with [structure](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/MIME_types#structure_of_a_mime_type):
```
type/subtype
type/subtype;parameter=value
```
👉 The returned promise is rejected with `Not Found` error if the provided `mimeType` is unavailable in [mime-db](https://github.com/jshttp/mime-db).
Examples:
```javascript
console.log(await db.mimeToExtensions('application/mp4'));
// Prints [ 'mp4', 'mpg4', 'mp4s', 'm4p' ]
console.log(await db.getExtensions('application/javascript; charset=utf-8'));
// Prints [ 'js' ]
```
### `db.extensionToMimes(extension)` or its alias `db.getTypes(extension)`
Returns a promise that fulfills with an array of MIME-types. **Note that this array of MIME-types is sorted in descending order of importance** according to the same [logic](https://github.com/jshttp/mime-types/blob/v3.0.1/mimeScore.js) used by [mime-types](https://github.com/jshttp/mime-types). If only one MIME-type is required, simply choose the first element from the array, or use the `db.getType()` [method](#dbextensiontomimeextension-or-its-alias-dbgettypeextension).
`extension`
String representing either of
- path, e.g. `dir/subdir/file.ext`
- file-extension with or without the leading dot, e.g. `mp4`, `.mp4`
- file-name, e.g. `file.mp4`, `file.version.1.2.0.mp4`
👉 The returned promise is rejected with `Not Found` error if the provided `mimeType` is unavailable in [mime-db](https://github.com/jshttp/mime-db).
Examples:
```javascript
console.log(await db.extensionToMimes('dir/subdir/path.version.js'));
console.log(await db.getTypes('js'));
console.log(await db.getTypes('.js'));
// Prints [ 'application/javascript', 'text/javascript' ]
```
### `db.extensionToMime(extension)` or its alias `db.getType(extension)`
Same as `db.getTypes()` [above](#dbextensiontomimesextension-or-its-alias-dbgettypesextension) but the returned promise resolves with only a single MIME-type instead of an array. The returned MIME-type has the highest score according to the [logic](https://github.com/jshttp/mime-types/blob/v3.0.1/mimeScore.js) used by [mime-types](https://github.com/jshttp/mime-types).
Examples:
```javascript
console.log(await db.getType('.deb'));
// Prints 'application/x-debian-package'
```
### `db.query(mimeType)`
Returns a promise that fulfills with the [mime-db data object](https://github.com/jshttp/mime-db/tree/v1.54.0#data-structure) for the provided MIME-type.
`mimeType`
String representing a MIME-type in the [form](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/MIME_types#structure_of_a_mime_type): `type/subtype`
👉 The returned promise is rejected with `Not Found` error if the provided `mimeType` is unavailable in [mime-db](https://github.com/jshttp/mime-db).
Examples:
```javascript
console.log(JSON.stringify(await db.query('application/javascript')));
// Prints '{"source":"apache","charset":"UTF-8","compressible":true,"extensions":["js"]}'
```
### `DB.mimeDbCdnVersion`
A constant that stores the [mime-db-cdn](https://www.npmjs.com/package/mime-db-cdn) release version data is fetched from.
### `DB.cdnBase`
A constant that stores the CDN via which data is accessed.
# Contribute
To register new media types in the database, [contribute directly to mime-db](https://github.com/jshttp/mime-db#contributing).
If you like this project, you can show your appreciation by
- [giving it a star](https://github.com/SomajitDey/mime-db-lite/stargazers) ⭐
- sponsoring me through 👇
[](https://buymeacoffee.com/SomajitDey)
Thank you 💚.