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AES Encrypt / Decrypt

Encrypt and decrypt text using AES-256-GCM with a passphrase. Runs entirely in your browser.

Developer Tools Runs locally No data sent
AES-256 GCM encrypt browser-only
Passphrase
Plaintext
0 chars
→
Ciphertext (Base64)
0 chars
Note: Uses AES-256-GCM with PBKDF2 key derivation (100,000 iterations, SHA-256). A random salt (16 bytes) and IV (12 bytes) are generated for each encryption. The output is a single Base64 string containing salt + IV + ciphertext. Your passphrase is never uploaded — all processing happens in your browser. To decrypt, you must use the same passphrase that was used to encrypt.

What is AES Encrypt / Decrypt?

AES Encrypt / Decrypt uses browser-side AES to protect plaintext with a passphrase and decrypt it again when you need the original content. It is useful for testing encryption flows, understanding IV and authentication tag behavior, and handling short secrets locally without sending them to a server.

How to Use AES Encrypt / Decrypt

  1. Choose whether you want to encrypt plaintext or decrypt ciphertext.
  2. Enter the text and the passphrase you want to use.
  3. Run the conversion and inspect the generated ciphertext or recovered plaintext.
  4. Copy the result for testing, demos, or local workflows.

Related Tools

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HMAC Generator
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Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 from text or file
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Base64 Encode / Decode
Encode or decode text and files to Base64
Understand AES Encrypt / Decrypt ▾
Example
Input Plaintext: "Secret message" - Key: "mykey" - Mode: AES-GCM-256
Output Base64-encoded ciphertext (includes IV + auth tag)
Common Use Cases
  • Encrypt notes, tokens, or payloads locally before sharing them
  • Test AES-GCM output formats during app or API development
  • Verify decryption behavior with known ciphertext and passphrase pairs
  • Demonstrate browser-side symmetric encryption without server calls
Why Use This Tool
  • Useful for validating AES-GCM behavior without setting up backend code.
  • Helps explain IVs, auth tags, and passphrase-based encryption flows.
  • Keeps plaintext and keys inside the browser for quick local testing.
Frequently Asked Questions
What is the difference between AES-CBC and AES-GCM?

AES-CBC provides confidentiality only and requires a separate MAC for integrity verification. AES-GCM provides both confidentiality and built-in authentication, making it the preferred choice for new systems.

Why does the ciphertext change every time I encrypt the same message?

A random IV (initialization vector) is generated for each encryption operation. This ensures that identical plaintexts produce different ciphertexts, preventing pattern analysis. The IV is stored alongside the ciphertext and used automatically during decryption.

How strong is AES-256?

AES-256 is considered computationally unbreakable with current technology. A brute-force attack would require more energy than the observable universe could provide; it is the gold standard for symmetric encryption.

Can I use this tool to encrypt files?

This tool is designed for text encryption. For file encryption, consider dedicated tools. However, you can encrypt Base64-encoded file content if needed.