aiogram/docs/api/downloading_files.md

How to download file?

Before you start, read the documentation for the getFile method.

Download file manually

First, you must get the file_id of the file you want to download. Information about files sent to the bot is contained in Message.

For example, download the document that came to the bot.

file_id = message.document.file_id

Then use the getFile method to get file_path.

file = await bot.get_file(file_id)
file_path = file.file_path

After that, use the download_file method from the bot object.

download_file(...)

Download file by file_path to destination. If you want to automatically create destination (#!python3 io.BytesIO) use default value of destination and handle result of this method.

Argument	Type	Description
file_path	#!python3 str	File path on Telegram server
destination	#!python3 Optional[Union[BinaryIO, pathlib.Path, str]]	Filename, file path or instance of #!python3 io.IOBase. For e.g. #!python3 io.BytesIO (Default: #!python3 None)
timeout	#!python3 int	Total timeout in seconds (Default: 30)
chunk_size	#!python3 int	File chunks size (Default: 64 kb)
seek	#!python3 bool	Go to start of file when downloading is finished. Used only for destination with #!python3 typing.BinaryIO type (Default: #!python3 True)

There are two options where you can download the file: to disk or to binary I/O object.

Download file to disk

To download file to disk, you must specify the file name or path where to download the file. In this case, the function will return nothing.

await bot.download_file(file_path, "text.txt")

Download file to binary I/O object

To download file to binary I/O object, you must specify an object with the #!python3 typing.BinaryIO type or use the default (#!python3 None) value.

In the first case, the function will return your object:

my_object = MyBinaryIO()
result: MyBinaryIO = await bot.download_file(file_path, my_object)
# print(result is my_object)  # True

If you leave the default value, an #!python3 io.BytesIO object will be created and returned.

result: io.BytesIO = await bot.download_file(file_path)