A PHP library to handle MIME Content-Type fields and their related file extensions.

2.0.0 2022-07-17 13:00 UTC


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A PHP library to handle MIME Content-Type fields and their related file extensions.


  • Parses MIME Content-Type fields
  • Supports the RFC 2045 specification
  • Provides utility functions for working with and determining info about MIME types
  • Map file extensions to MIME types and vice-versa
  • Automatically update the mapping between MIME types and file extensions from the most authoritative sources available, Apache's documentation and the project.
  • PHPUnit tested, 100% test coverage
  • PHPStan tested, level 9
  • Psalm tested


MimeMap is a fork of PEAR's MIME_Type package. See all the original contributors.

Note that in comparison with PEAR's MIME_Type, this library has a different scope, mainly focused on finding the mapping between each MIME type and its generally accepted file extensions. Features to detect the MIME type of a file have been removed. The symfony/http-foundation library and its MimeTypeGuesser API are the suggested components to cover that use case.

Alternative packages

MimeMap's main difference from similar packages is that it provides functionalities to use multiple type-to-extension maps and to change the mapping either at runtime or statically in PHP classes. See wgenial/php-mimetyper for a nice list of alternative PHP libraries for MIME type handling.


$ composer require fileeye/mimemap



The package comes with a default map that describes MIME types and the file extensions normally associated to each MIME type. The map also stores information about MIME type aliases, (alternative media/subtype combinations that describe the same MIME type), and the descriptions of most MIME types and of the acronyms used.

For example: the MIME type 'application/pdf'

  • is described as 'PDF document'
  • the PDF acronym is described as 'PDF: Portable Document Format'
  • is normally using a file extension 'pdf'
  • has aliases such as 'application/x-pdf', 'image/pdf'

The API the package implements is pretty straightforward:

  1. You have a MIME type, and want to get the file extensions normally associated to it:
use FileEye\MimeMap\Type;
$type = new Type('image/jpeg');

// will print ['jpeg', 'jpg', 'jpe']

// will print 'jpeg'

// When passing an alias to a MIME type, the API will
// return the extensions to the parent type:
$type = new Type('image/pdf');

// will print 'pdf' which is the default extension for 'application/pdf'
  1. Viceversa, you have a file extensions, and want to get the MIME type normally associated to it:
use FileEye\MimeMap\Extension;
$ext = new Extension('xar');

// will return ['application/vnd.xara', 'application/x-xar']

// will return 'application/vnd.xara'
  1. You have a raw MIME Content-Type string and want to add a parameter:
use FileEye\MimeMap\Type;
$type = new Type('text / (Unstructured text)  plain  ; charset = (UTF8, not ASCII) utf-8');
$type->addParameter('lang', 'it', 'Italian');

echo $type->toString(Type::SHORT_TEXT);
// will print 'text/plain'

echo $type->toString(Type::FULL_TEXT);
// will print 'text/plain; charset="utf-8"; lang="it"'

echo $type->toString(Type::FULL_TEXT_WITH_COMMENTS);
// will print 'text/plain (Unstructured text); charset="utf-8" (UTF8, not ASCII), lang="it" (Italian)'
  1. You have a MIME Content-Type string and want to add the type's description as a comment:
use FileEye\MimeMap\Type;
$type = new Type('text/html');

$type_desc = $type->getDescription();
echo $type->toString(Type::FULL_TEXT_WITH_COMMENTS);
// will print 'text/html (HTML document)'

// Setting the $include_acronym parameter of getDescription to true
// will extend the description to include the meaning of the acronym
$type_desc = $type->getDescription(true);
echo $type->toString(Type::FULL_TEXT_WITH_COMMENTS);
// will print 'text/html (HTML document, HTML: HyperText Markup Language)'

Specify alternative MIME type mapping

You can also alter the default map at runtime, either by adding/removing mappings, or indicating to MimeMap to use a totally different map. The alternative map must be stored in a PHP class that extends from \FileEye\MimeMap\Map\AbstractMap.

  1. You want to add an additional MIME type to extension mapping to the default class:
use FileEye\MimeMap\Extension;
use FileEye\MimeMap\MapHandler;
use FileEye\MimeMap\Type;
$map = MapHandler::map();
$map->addTypeExtensionMapping('foo/bar', 'baz');

$type = new Type('foo/bar');
$default_extension = $type->getDefaultExtension();
// will return 'baz'

$ext = new Extension('baz');
$default_type = $ext->getDefaultExtension();
// will return 'foo/bar'
  1. You want to set an alternative map class as default:
use FileEye\MimeMap\Extension;
use FileEye\MimeMap\MapHandler;
use FileEye\MimeMap\Type;
  1. You can also use the alternative map just for a single Type or Extension object:
use FileEye\MimeMap\Extension;
use FileEye\MimeMap\Type;
$type = new Type('foo/bar', 'MyProject\MyMap');
$ext = new Extension('baz', 'MyProject\MyMap');


Updating the extension mapping code

The default extension-to-type mapping class can be updated from the sources' code repositories, using the fileeye-mimemap utility:

$ cd [project_directory]/vendor/bin
$ fileeye-mimemap update

By default, the utility fetches a mapping source available from the Apache's documentation website, merges it with another mapping source from the project, then integrates the result with any overrides specified in the resources/default_map_build.yml file, and finally updates the PHP file where the \FileEye\MimeMap\Map\DefaultMap class is stored.

The --script and --class options allow specifying a different update logic and a different class file to update. Type

$ fileeye-mimemap update --help

to get more information.