base64 — Base16, Base32, Base64 Data Encodings

The base64 module provides functions for encoding binary data to printable ASCII characters and decoding such encodings back to binary data. This is typically used to safely send binary data (like images or compiled code) as text over protocols that are designed to handle only text, such as HTTP headers or JSON.

import base64

Basic Base64 Encoding/Decoding

Note: The functions work strictly with bytes, so strings must be encoded before passing them to the functions, and decoded afterward.

import base64

text = "Hello, Python developers!"
# Convert to bytes
byte_data = text.encode('utf-8')

# 1. Encode to Base64
encoded_bytes = base64.b64encode(byte_data)

print(encoded_bytes) 
# b'SGVsbG8sIFB5dGhvbiBkZXZlbG9wZXJzIQ=='

print(encoded_bytes.decode('utf-8'))
# SGVsbG8sIFB5dGhvbiBkZXZlbG9wZXJzIQ==

# 2. Decode back to original
decoded_bytes = base64.b64decode(encoded_bytes)
original_text = decoded_bytes.decode('utf-8')
print(original_text) # Hello, Python developers!

URL-Safe Encoding

Standard Base64 contains + and / characters, which have special meanings in URLs. To send Base64 in a URL, use urlsafe_b64encode, which substitutes - and _ instead.

import base64

payload = b"\x00\x11\x22\x33\x44" # Binary payload

# Standard returns: b'ABEiM0Q='
# URL safe returns: b'ABEiM0Q=' (same if no tricky chars, but vital mathematically)
url_safe = base64.urlsafe_b64encode(payload)

Other Encodings (Base16 / Base32)

Base16 exactly corresponds to simple hexadecimal representation. Base32 is a larger set but doesn't use lowercase letters.

import base64

data = b"Some data"

print(base64.b16encode(data)) # b'536F6D65... ' (Hex)
print(base64.b32encode(data)) # b'KNXW2ZJA...'

API Reference

Modern API

Legacy API (For Files)