mime

MIME type detection and content-type helpers for Remix. This package maps extensions to MIME types and provides utilities for charset and compressibility checks.

Features

• MIME Detection - Detect MIME types from extensions and filenames
• Content-Type Helpers - Build Content-Type values with charset handling
• Compression Signals - Check whether a media type is likely compressible
• Generated Data - Built from mime-db

Installation

npm i remix

Usage

detectMimeType(extension)

Detects the MIME type for a given file extension or filename.

import { detectMimeType } from 'remix/mime'

detectMimeType('txt') // 'text/plain'
detectMimeType('.txt') // 'text/plain'
detectMimeType('file.txt') // 'text/plain'
detectMimeType('path/to/file.txt') // 'text/plain'
detectMimeType('unknown') // undefined

detectContentType(extension)

Detects the Content-Type header value for a given file extension or filename, including charset for text-based types. See mimeTypeToContentType for charset logic.

import { detectContentType } from 'remix/mime'

detectContentType('css') // 'text/css; charset=utf-8'
detectContentType('.json') // 'application/json; charset=utf-8'
detectContentType('image.png') // 'image/png'
detectContentType('path/to/file.unknown') // undefined

isCompressibleMimeType(mimeType)

Checks if a MIME type is known to be compressible.

import { isCompressibleMimeType } from 'remix/mime'

isCompressibleMimeType('text/html') // true
isCompressibleMimeType('application/json') // true
isCompressibleMimeType('image/png') // false
isCompressibleMimeType('video/mp4') // false

For convenience, the function also accepts a full Content-Type header value:

import { isCompressibleMimeType } from 'remix/mime'

isCompressibleMimeType('text/html; charset=utf-8') // true
isCompressibleMimeType('application/json; charset=utf-8') // true
isCompressibleMimeType('image/png; charset=utf-8') // false
isCompressibleMimeType('video/mp4; charset=utf-8') // false

mimeTypeToContentType(mimeType)

Converts a MIME type to a Content-Type header value, adding ; charset=utf-8 to text-based MIME types: text/* (except text/xml which has built-in encoding declarations), application/json, application/javascript, and all +json suffixed types. All other types are returned unchanged.

import { mimeTypeToContentType } from 'remix/mime'

mimeTypeToContentType('text/css') // 'text/css; charset=utf-8'
mimeTypeToContentType('application/json') // 'application/json; charset=utf-8'
mimeTypeToContentType('application/ld+json') // 'application/ld+json; charset=utf-8'
mimeTypeToContentType('image/png') // 'image/png'

defineMimeType(definition)

Registers or overrides a MIME type for one or more file extensions.

import { defineMimeType } from 'remix/mime'

defineMimeType({
  extensions: ['myformat'],
  mimeType: 'application/x-myformat',
})

You can also optionally configure the charset and whether the MIME type is compressible:

defineMimeType({
  extensions: ['myformat'],
  mimeType: 'application/x-myformat',
  compressible: true,
  charset: 'utf-8',
})

License

MIT