Password Checker v2.1

Password Checker v2 checks whether a password appears in the Have I Been Pwned password database.

It uses the k-anonymity range API:

• Your full password is never sent over the internet.
• The script only sends the first 5 characters of the SHA-1 hash.
• The match happens locally on your computer.

Why v2 is easier to use

Version 2.1 is designed for normal terminal users, not just programmers:

• Hidden password entry when you run it without arguments
• Clearer messages
• Better error handling
• Batch checking from a text file
• No external Python packages required
• Native desktop GUI for users who do not want a terminal

Get it from GitHub

If you do not have the project on your computer yet, download it like this:

cd "$HOME/Applications"
git clone https://github.com/ViliTajnic/passwordchecker.git passwdchk
cd passwdchk

This creates the local folder $HOME/Applications/passwdchk and connects it to the GitHub repository.

If you prefer to see the username explicitly, $HOME/Applications/passwdchk is the same idea as /Users/<your-username>/Applications/passwdchk on macOS.

If you already have the folder and just want the newest version:

cd "$HOME/Applications/passwdchk"
git pull origin master

If you want to check whether you have local changes first:

git status

If git status shows modified files, commit or stash them before running git pull to avoid merge conflicts.

Requirements

• Python 3
• Internet connection

This version uses only the Python standard library, so you do not need to install requests.

Quick start

Run the script:

python3 checkmypass.py

You will be prompted to enter a password privately. It will not be shown on screen while you type.

Usage

Show help:

python3 checkmypass.py --help

Check one password interactively:

python3 checkmypass.py

Check one or more passwords directly from the command line:

python3 checkmypass.py password1 password2

This works, but it is less safe because command history may store the password.

Check passwords from a file:

python3 checkmypass.py --file passwords.txt

The file should contain one password per line.

Example output

Password Checker v2.0
Checking 1 password(s)...
Password 1: found in known breach data 52,256,179 times. Do not use this password.
Check completed successfully.

If a password is not found, the script will say so, but that does not guarantee the password is strong. A long, unique password is still the right choice.

Desktop app

The project also includes a native desktop interface built with Tkinter.

Run it from source:

python3 passwordchecker_gui.py

Desktop features:

• Hidden password field
• One-click single password check
• File picker for batch checking
• Plain-language results
• No password echo in the interface

Standalone executables

This repo builds both the command-line tool and the desktop app for macOS and Windows.

Local macOS build:

./scripts/build_macos.sh

The executable will be created at dist/passwordchecker.

The desktop app will be created at dist/Password Checker.app.

Local Windows build:

.\scripts\build_windows.ps1

The executable will be created at dist\passwordchecker.exe.

The desktop app will be created at dist\passwordchecker-gui.exe.

Windows binaries should be built on Windows, and macOS binaries should be built on macOS. For that reason, the repo also includes a GitHub Actions workflow that builds both platforms automatically on native runners.

GitHub Actions output:

• passwordchecker-cli-macos
• passwordchecker-gui-macos
• passwordchecker-cli-windows
• passwordchecker-gui-windows

Notes

• If the API cannot be reached, the script prints a plain-language error message.
• Empty lines in a password file are ignored.
• Direct command-line passwords are supported for convenience, but interactive mode is the safest option.