Main Module

Mutagen aims to be an all purpose multimedia tagging library.

import mutagen.[format]
metadata = mutagen.[format].Open(filename)

metadata acts like a dictionary of tags in the file. Tags are generally a list of string-like values, but may have additional methods available depending on tag or format. They may also be entirely different objects for certain keys, again depending on format.

mutagen.version = (1, 43, 1)

Version tuple.

mutagen.File(filething, options=None, easy=False)

Guess the type of the file and try to open it.

The file type is decided by several things, such as the first 128 bytes (which usually contains a file type identifier), the filename extension, and the presence of existing tags.

If no appropriate type could be found, None is returned.

  • filething (filething) –
  • options – Sequence of FileType implementations, defaults to all included ones.
  • easy (bool) – If the easy wrappers should be returnd if available. For example EasyMP3 instead of MP3.

A FileType instance for the detected type or None in case

the type couln’t be determined.

Return type:



MutagenError – in case the detected type fails to load the file.

mutagen.version_string = '1.43.1'

Version string.

Base Classes

class mutagen.FileType(filething, **kwargs)

Bases: mutagen._util.DictMixin

Parameters:filething (filething) – A filename or a file-like object

Subclasses might take further options via keyword arguments.

An abstract object wrapping tags and audio stream information.

Each file format has different potential tags and stream information.

FileTypes implement an interface very similar to Metadata; the dict interface, save, load, and delete calls on a FileType call the appropriate methods on its tag data.


contains length, bitrate, sample rate


metadata tags, if any, otherwise None


Adds new tags to the file.

Raises:mutagen.MutagenError – if tags already exist or adding is not possible.

Remove tags from a file.

In cases where the tagging format is independent of the file type (for example mutagen.id3.ID3) all traces of the tagging format will be removed. In cases where the tag is part of the file type, all tags and padding will be removed.

The tags attribute will be cleared as well if there is one.

Does nothing if the file has no tags.

Raises:mutagen.MutagenError – if deleting wasn’t possible

A list of mime types (mutagen.text)

Returns:stream information and comment key=value pairs.
Return type:text
save(filething=None, **kwargs)

Save metadata tags.

Raises:MutagenError – if saving wasn’t possible
class mutagen.Tags

Tags is the base class for many of the tag objects in Mutagen.

In many cases it has a dict like interface.

Returns:tag information
Return type:text
class mutagen.Metadata(filething=None, **kwargs)

Bases: mutagen.Tags

Parameters:filething (filething) – a filename or a file-like object or None to create an empty instance (like ID3())

Like Tags but for standalone tagging formats that are not solely managed by a container format.

Provides methods to load, save and delete tags.


Remove tags from a file.

In most cases this means any traces of the tag will be removed from the file.

Parameters:filething (filething) – or None
Raises:MutagenError – if deleting wasn’t possible
save(filething=None, **kwargs)

Save changes to a file.

Parameters:filething (filething) – or None
Raises:MutagenError – if saving wasn’t possible
class mutagen.StreamInfo

Abstract stream information object.

Provides attributes for length, bitrate, sample rate etc.

See the implementations for details.

Returns:Print stream information
Return type:text
class mutagen.PaddingInfo

Abstract padding information object.

This will be passed to the callback function that can be used for saving tags.

def my_callback(info: PaddingInfo):
    return info.get_default_padding()

The callback should return the amount of padding to use (>= 0) based on the content size and the padding of the file after saving. The actual used amount of padding might vary depending on the file format (due to alignment etc.)

The default implementation can be accessed using the get_default_padding() method in the callback.


The amount of padding left after saving in bytes (can be negative if more data needs to be added as padding is available)


The amount of data following the padding


The default implementation which tries to select a reasonable amount of padding and which might change in future versions.

Returns:Amount of padding after saving
Return type:int
class mutagen.MutagenError

Base class for all custom exceptions in mutagen

New in version 1.25.

Internal Classes

Utility classes for Mutagen.

You should not rely on the interfaces here being stable. They are intended for internal use in Mutagen only.

class mutagen._util.DictMixin

Implement the dict API using keys() and __*item__ methods.

Similar to UserDict.DictMixin, this takes a class that defines __getitem__, __setitem__, __delitem__, and keys(), and turns it into a full dict-like object.

UserDict.DictMixin is not suitable for this purpose because it’s an old-style class.

This class is not optimized for very large dictionaries; many functions have linear memory requirements. I recommend you override some of these functions if speed is required.

class mutagen._util.DictProxy(*args, **kwargs)

Bases: mutagen._util.DictMixin

Other Classes and Functions

class mutagen.text

This type only exists for documentation purposes. It represents unicode under Python 2 and str under Python 3.

class mutagen.bytes

This type only exists for documentation purposes. It represents str under Python 2 and bytes under Python 3.

class mutagen.fspath

This type only exists for documentation purposes. It represents a file name which can be str or unicode under Python 2 and bytes or str under Python 3.

class mutagen.fileobj
This type only exists for documentation purposes. A file-like object.
See Working with File-like Objects for more information.
class mutagen.filething

This type only exists for documentation purposes. Either a fspath or a fileobj.


A function you can implement and pass to various save() methods for controlling the amount of padding to use. See Tag Padding for more information.

Parameters:info (PaddingInfo) –
Returns:The amount of padding to use
Return type:int