Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsUse Python’s built-in bytes.fromhex() method to convert hexadecimal text into bytes. Each pair of hex digits becomes one byte, and ASCII whitespace between digits is ignored.
Convert a hex string with bytes.fromhex()
Call the method on bytes and pass the hexadecimal string:
hex_string = "2Ef0 F1f2"
data = bytes.fromhex(hex_string)
print(data) # b'.xf0xf1xf2'The string contains four pairs of hexadecimal digits, so the result contains four bytes. The space between pairs is allowed. Python’s built-in types documentation shows this conversion and specifies that ASCII whitespace is ignored.
Input format and whitespace
Supply two hexadecimal digits for each byte. For example, "2ef0f1f2" represents the same bytes as "2e f0 f1 f2". Since Python 3.7, bytes.fromhex() skips all ASCII whitespace, not just ordinary spaces.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
Do not assume the method will clean up other formatting. Prefixes such as 0x, commas, colons, or arbitrary non-hex characters are not covered by the documented whitespace behavior. If your input uses such formatting, remove or validate it deliberately before conversion rather than treating it as plain hex.
Use binascii.unhexlify() as an alternative
The standard-library binascii module also converts hexadecimal text to binary data:
import binascii
data = binascii.unhexlify("2ef0f1f2")In the documented Python 3.10 API, unhexlify() requires an even number of hexadecimal digits; a malformed length raises binascii.Error. The Python 3.10 binascii documentation describes bytes.fromhex() as more liberal about whitespace. For typical string input—especially when whitespace may occur—bytes.fromhex() is the simpler choice.
Convert the bytes back to hexadecimal text
Use .hex() on the resulting bytes to get a string with two hexadecimal digits per byte:
data = bytes.fromhex("2ef0f1f2")
hex_again = data.hex()
print(hex_again) # '2ef0f1f2'The Python built-in types documentation also describes separators for formatting the hexadecimal output.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Handle invalid input and version differences
For untrusted or externally supplied text, let conversion errors reach a suitable validation boundary or catch them there so the application can report invalid data or recover. The documented behavior does not establish one exception type for every malformed bytes.fromhex() case across Python versions, so check the documentation for the version your application supports before relying on a specific exception.
There are two relevant version notes: Python 3.7 expanded ignored whitespace to all ASCII whitespace, and Python 3.14 added support for ASCII bytes and bytes-like objects as the method’s input. If you pass anything other than a str, check that the deployed Python version supports it in the current built-in types documentation.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
