BrainCoder
Encode & DecodeNothing uploaded

AES Encrypt / Decrypt

AES-256-GCM encryption

Free forever — no sign-up, nothing uploaded. Files never leave your device.

braincoder.app/use/aes-encryption

AES Encrypt / Decrypt

AES-256-GCM encryption

Drop your file here

or browse from your device

Browse files

document.pdf

1.2 MB

report.pdf

860 KB

100% private

Nothing is uploaded — everything runs in your browser.

Free forever

No account or payment required.

No sign-up

Open the tool and start using it right away.

Local processing

Processing time depends on your input and device.

About this tool

Encrypt and decrypt text with AES-256-GCM and PBKDF2 key derivation. Produces a portable JSON envelope you can decrypt on any device.

The BrainCoder AES Encrypt & Decrypt tool provides symmetric encryption using the Advanced Encryption Standard (AES) — the same algorithm protecting everything from HTTPS connections to government classified data. Enter your plaintext, provide a passphrase, and the tool encrypts your data into an unreadable ciphertext using AES-GCM with PBKDF2 key derivation.

Security is handled properly: your passphrase is stretched through thousands of PBKDF2 iterations to derive a secure encryption key, and a unique initialization vector (IV) is generated for each encryption operation. This means even encrypting the same text with the same password produces different ciphertext, which is a hallmark of secure encryption. The tool uses the Web Crypto API — the same cryptographic engine in your browser.

All encryption and decryption happens locally. Your plaintext, passphrase, and ciphertext never leave your browser. This makes it suitable for encrypting sensitive notes, passwords, API keys, or any data you want to protect before storing it in a file, email, or cloud service.

Key features

Everything you get with AES Encrypt / Decrypt — no premium upsell.

AES-256-GCM encryption (military-grade security)

PBKDF2 key derivation with configurable iterations

Unique IV generated for each encryption operation

Compatible with other AES-GCM implementations

Outputs ciphertext as Base64 for easy storage

Zero data transmission — entirely in-browser

How to use AES Encrypt / Decrypt

Follow the steps below to use the tool.

  1. 1

    Enter plaintext

    Type or paste the text you want to encrypt into the plaintext field. This could be a password, API key, private note, or any sensitive data.

  2. 2

    Provide a strong passphrase

    Enter a passphrase that will be used to derive the encryption key. Use a strong, unique passphrase — the security of your encrypted data depends on it.

  3. 3

    Click Encrypt

    The tool derives an AES-256 key from your passphrase using PBKDF2, generates a random IV, and produces an encrypted ciphertext output.

  4. 4

    Copy and store the ciphertext

    Copy the Base64-encoded ciphertext and store it safely. To decrypt later, paste the ciphertext, enter the same passphrase, and click Decrypt.

Still free, still private — your files never leave your device.

Launch AES Encrypt / Decrypt

Frequently asked questions

Quick answers before you launch the tool.