Developer Tools

AES Decrypt Guide

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

What this guide covers

Use this AES Decrypt tool to reverse AES-encrypted Base64 text using the original passphrase. It is useful for browser-side decryption tests, reversible development workflows, encrypted sample validation, and confirming that AES-encrypted values can be decoded back into readable text correctly.

This guide explains when to use AES 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 AES Decrypt

Decrypt AES ciphertext back into readable text quickly
Useful for testing passphrase-based encryption workflows
Helps verify AES round-trip behavior
Useful for debugging encrypted samples
Runs directly in the browser

How to use AES Decrypt

Enter the passphrase on the first line
Paste the Base64 ciphertext below it
Click Run Tool to decrypt the value
Review the plaintext output
Use the exact same passphrase that was used for encryption

Best use cases

Reversing AES-encrypted samples
Testing passphrase-based browser workflows
Checking encrypted development values
Validating AES round-trips
Debugging encrypted demo data

Common mistakes

The wrong passphrase is used

Fix: Use the exact same passphrase that was used during encryption.

The ciphertext is not valid Base64 or not actually AES output

Fix: Paste valid Base64 ciphertext produced by the matching AES encrypt workflow.

The input format is reversed

Fix: Put the passphrase first and the ciphertext below it.

The output is empty or broken

Fix: This usually means the passphrase or ciphertext format is wrong.

The user expects another cipher to work here

Fix: Use the matching decrypt tool for the actual cipher.

Use the tool

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

Open AES Decrypt