Detects mime types using magic bytes / magic numbers

dev-master 2019-09-27 16:46 UTC

This package is auto-updated.

Last update: 2024-01-28 03:09:06 UTC


Uses magic numbers (aka magic bytes) to detect the content media type.


composer require rikudou/mime-type-detector


Simply construct a new object and call the getMimeType() method:


use Rikudou\MimeTypeDetector\MimeTypeDetector;

$mimeTypeDetector = new MimeTypeDetector();
// will print image/jpeg

This can be kind of slow, because all definitions are checked, even those like apk and jar which need looking into the zip archive to determine the type of content.

If you don't need checking for those, you can disable looking into archives (see below in advanced usage).

Advanced usage

Custom definitions

You can supply custom mime type definitions as the second argument:


use Rikudou\MimeTypeDetector\MimeTypeDetector;

/** @var array $myDefinitions */

$detector = new MimeTypeDetector(null, $myDefinitions);

The definitions format is described in ConfigNormalizerInterface and basically goes as this:

'mime_types' => [
    'mimeType' => [
        0 => [
            'length' => 1,
            'offset' => 0,
            'binary' => null,
            'archive' => false,
            'parent' => null,
            'files' => [
                0 => [
                    'name' => 'path/to/file/in/archive'
                    'dir' => false,
                    'pattern' => false,
                    'binary' => null,
                    'content' => null
            'bytes' => [
                0 => 'ff',

List of properties

  • mime_types - This is the root array key and must be present.
  • mediaType - This is the media/mime type, e.g. image/jpeg which is also a key of the array definitions. The value may either be array of definitions or a definition itself.
  • parent - The parent definition, all properties of the parent will be merged with the child definition. All the properties below that specify required are not required if the parent has them set. Null means no parent. The parent must exist and can (and should) be defined after the child.
  • length required - The length of the bytes to get from the file.
  • offset - It's the offset in bytes from beginning of file.
  • bytes required - The bytes that should be at given offset with given length. Can be a string or an array of strings. The bytes are checked in an or relation, e.g. if any one matches, it's a match. Can include * and ? for any characters and any single character respectively (shell patterns).
  • binary - Whether the file should be binary or not. Can be null which means no check.
  • archive - Whether the file is an archive, which implies that files inside the archive should be checked for existence/content etc.
  • files required if archive is true - Array of files inside the archive that should be checked. Can be a string or array of values:
    • name - the name of the file that should be present in the archive,
    • dir - set to true if the name is a path to directory, not a file. The archive must be extracted for this to work, so use with caution,
    • pattern - set to true if the name contains a shell pattern (*, ?). The archive must be extracted for this to work, so use with caution,
    • binary - whether the file in name should be binary or not. Null means no check,
    • content - If not null, check if the file content equals to given string

Turning off archive traversing

As archive traversing can be kind of slow, you can disable it, if you don't need any of these types:

  • application/vnd.android.package-archive - Android apk file
  • application/java-archive - Java jar archive
  • application/x-xpinstall - Mozilla xpi files
  • application/epub+zip - epub books
  • application/x-itunes-ipa - iOS ipa files (these are particularly resource expensive to detect)
  • application/vnd.google-earth.kmz - Google Earth kmz files
  • application/vnd.openxmlformats-officedocument.wordprocessingml.document - Microsoft Word files
  • application/vnd.openxmlformats-officedocument.spreadsheetml.sheet - Microsoft Excel files
  • application/vnd.oasis.opendocument.presentation - OpenDocument presentation files
  • application/vnd.oasis.opendocument.spreadsheet - OpenDocument sheet files
  • application/vnd.oasis.opendocument.text - OpenDocument document files
  • application/vnd.openxmlformats-officedocument.presentationml.presentation - Microsoft PowerPoint files

All of them will be reported as application/zip.

To turn these off simply set a custom ConfigNormalizer with $advancedDetection set to false:


use Rikudou\MimeTypeDetector\Config\ConfigNormalizer;
use Rikudou\MimeTypeDetector\MimeTypeDetector;

$config = new ConfigNormalizer(false);
$detector = new MimeTypeDetector($config);

Turning off individual mime types

If you don't want to check for certain mime types (for example because you need to detect e.g. apk files but don't want to suffer the resource penalty for all other zip-based files), you can turn them off using custom ConfigNormalizer:


use Rikudou\MimeTypeDetector\Config\ConfigNormalizer;
use Rikudou\MimeTypeDetector\MimeTypeDetector;

$config = new ConfigNormalizer(true, [
]); // this will check all types but ipa files
$detector = new MimeTypeDetector($config);

$config = new ConfigNormalizer(false, [
]); // this won't check any zip-based types and jpeg files

List of all types and their detections is in mime.yaml.

Create config using config builder

The config builder is there to help you create config for mime types and turn on and off detection for groups of types:


use Rikudou\MimeTypeDetector\Config\ConfigBuilder;

$config = ConfigBuilder::create()

By default when you call just ConfigBuilder::create() everything is enabled so you don't need to call e.g. withImages() like in the example above. But if you want to disable image detection, you can use withoutImages() - every with method has a without counterpart.

There is also a static method createSaneDefaults() which can be used.


use Rikudou\MimeTypeDetector\Config\ConfigBuilder;

$config1 = ConfigBuilder::createSaneDefaults()

$config2 = ConfigBuilder::create()

The two configs above mean the same thing.