Automatic Installation

To install Telethon, simply do:

pip3 install telethon

Needless to say, you must have Python 3 and PyPi installed in your system. See and for more.

If you already have the library installed, upgrade with:

pip3 install --upgrade telethon

You can also install the library directly from GitHub or a fork:

# pip3 install git+
$ git clone
$ cd Telethon/
# pip install -Ue .

If you don’t have root access, simply pass the --user flag to the pip command. If you want to install a specific branch, append @branch to the end of the first install command.

By default the library will use a pure Python implementation for encryption, which can be really slow when uploading or downloading files. If you don’t mind using a C extension, install cryptg via pip or as an extra:

pip3 install telethon[cryptg]

Manual Installation

  1. Install the required pyaes (GitHub | PyPi) and rsa (GitHub | PyPi) modules:

    pip3 install pyaes rsa
  2. Clone Telethon’s GitHub repository:

    git clone
  3. Enter the cloned repository:

    cd Telethon
  4. Run the code generator:

    python3 gen
  5. Done!

To generate the method documentation, python3 gen docs.

Optional dependencies

If pillow is installed, large images will be automatically resized when sending photos to prevent Telegram from failing with “invalid image”. Official clients also do this.

If aiohttp is installed, the library will be able to download WebDocument media files (otherwise you will get an error).

If hachoir is installed, it will be used to extract metadata from files when sending documents. Telegram uses this information to show the song’s performer, artist, title, duration, and for videos too (including size). Otherwise, they will default to empty values, and you can set the attributes manually.

If cryptg is installed, encryption and decryption will be made in C instead of Python which will be a lot faster. If your code deals with a lot of updates or you are downloading/uploading a lot of files, you will notice a considerable speed-up (from a hundred kilobytes per second to several megabytes per second, if your connection allows it). If it’s not installed, pyaes will be used (which is pure Python, so it’s much slower).