Developer Tools

XOR Decrypt Guide

Learn when to use XOR Decrypt, how to use it correctly, and how to avoid common mistakes.

What this guide covers

Use this XOR Decrypt tool to reverse XOR-encrypted hexadecimal text using the same key that was used for encryption. It is useful for CTF practice, cryptography basics, byte-level debugging, reversible obfuscation demos, and understanding how XOR transforms can be undone when the key is known.

This guide explains when to use XOR Decrypt, how to get a cleaner result, and which mistakes to avoid before moving on to related tools or the main tool page.

Why use XOR Decrypt

Decrypt XOR-encrypted hex with the original key quickly
Useful for CTFs and basic crypto exercises
Helps explain how XOR is reversed with the same key
Useful for debugging encoded samples and toy ciphers
Runs directly in the browser

How to use XOR Decrypt

Enter the key on the first line and the hexadecimal ciphertext below it
Click Run Tool to decrypt the value
Review the readable plaintext output
Copy the result for analysis or notes
Use XOR Encrypt to create matching test samples

Best use cases

Reversing XOR challenge samples
Learning how XOR decryption works
Inspecting repeating-key XOR outputs
Debugging toy crypto examples
Practicing basic CTF decryption tasks

Common mistakes

The wrong key is used

Fix: Use exactly the same key that was used to encrypt the text.

The ciphertext is not valid hex

Fix: Enter only hexadecimal characters with an even total length.

The user pastes plaintext instead of XOR hex

Fix: This tool expects hexadecimal ciphertext, not ordinary text.

The input format is reversed

Fix: Put the key first and the hex ciphertext below it.

The user expects modern secure cryptanalysis

Fix: This tool only reverses simple XOR when the key is already known.

Use the tool

Ready to run XOR Decrypt? Open the main tool page to enter your input, generate the result, and copy or download the output.

Open XOR Decrypt