Text encryption & decryption tool
Free client-side Text encryption & decryption tool web utility.
Client-Side AES Text Encryption & Decryption
Encrypt and decrypt confidential notes, credentials, and messages in browser memory using military-grade AES-256-GCM and PBKDF2 key derivation.
Encrypted Ciphertext (Base64 Bundle)
About this tool
How to use it
- Choose whether you want to encrypt a new secret message or decrypt an existing ciphertext bundle.
- Enter your secret passphrase or shared password and select your cipher (AES-GCM 256-bit recommended).
- Paste your plaintext or encrypted ciphertext into the input box and click Encrypt / Decrypt.
- Copy the resulting Base64 cryptographic payload bundle containing salt, IV, and authenticated ciphertext.
Why it matters
Sending sensitive passwords, API keys, or confidential notes through web servers exposes them to logging and security breaches. Client-side Web Cryptography guarantees that plaintext never leaves your browser memory.
When to use it
Use this tool to safely share passwords with teammates over insecure messaging channels, encrypt offline notes, or verify AES-256 cryptographic payloads.
Common questions
What is the difference between AES-GCM and AES-CBC?
AES-GCM (Galois/Counter Mode) provides authenticated encryption, guaranteeing both confidentiality and integrity with built-in tamper detection. AES-CBC only provides confidentiality and requires separate HMAC authentication.
How are encryption keys derived from passwords?
The tool uses PBKDF2 (Password-Based Key Derivation Function 2) with HMAC-SHA256 and 100,000 computation rounds combined with a cryptographically random 16-byte salt to resist brute-force attacks.
Can someone decrypt my message without the passphrase?
No. AES-256 is mathematically unbroken. Without knowledge of the exact passphrase, cracking the ciphertext would require astronomical computational power.
Does toolsfor.co store my passphrase or messages?
No. All encryption and key generation executes in your device's browser memory using window.crypto.subtle. Nothing is transmitted over the network.