Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Python One Time Password library, ported from ROTP (
branch: master

This branch is 15 commits ahead, 118 commits behind mdp:master

Merge pull request #6 from jboning/timing

Timing-attack-resistant string comparison
latest commit 55ee6f621c
@nathforge authored


PYOTP - The Python One Time Password Library

A Python library for generating one time passwords according to RFC 4226 and the HOTP RFC , ported from Mark Percival's ROTP .

This is compatible with Google Authenticator apps available for Android and iPhone, and now in use on GMail

Quick overview of using One Time Passwords on your phone

  • OTP's involve a shared secret, stored both on the phone and the server
  • OTP's can be generated on a phone without internet connectivity(AT&T mode)
  • OTP's should always be used as a second factor of authentication(if your phone is lost, you account is still secured with a password)
  • Google Authenticator allows you to store multiple OTP secrets and provision those using a QR Code(no more typing in the secret)


pip install pyotp


Time based OTP's

totp = pyotp.TOTP('base32secret3232') # => 492039

# OTP verified for current time
totp.verify(492039) # => True
totp.verify(492039) # => False

Counter based OTP's

hotp = pyotp.HOTP('base32secret3232') # => 260182 # => 55283 # => 316439

# OTP verified with a counter
hotp.verify(316439, 1401) # => True
hotp.verify(316439, 1402) # => False

Generating a Base32 Secret key

pyotp.random_base32() # returns a 16 character base32 secret. Compatible with Google Authenticator

Google Authenticator Compatible

The library works with the Google Authenticator iPhone and Android app, and also includes the ability to generate provisioning URI's for use with the QR Code scanner built into the app.

totp.provisioning_uri("") # => 'otpauth://totp/'
hotp.provisioning_uri("", 0) # => 'otpauth://hotp/'

This can then be rendered as a QR Code which can then be scanned and added to the users list of OTP credentials.

Working example

Scan the following barcode with your phone, using Google Authenticator

QR Code for OTP

Now run the following and compare the output

import pyotp
totp = pyotp.TOTP("JBSWY3DPEHPK3PXP")
print "Current OTP: %s" %



  • Ported to Python

See also:

Original Ruby version of ROTP by Mark Percival - ROTP PHP port of ROTP by Le Lag - OTPHP

Something went wrong with that request. Please try again.