Encrypt and decrypt text with AES-256-GCM. Nothing leaves your browser.
AES-256-GCM (Advanced Encryption Standard with Galois/Counter Mode) is the gold standard for symmetric encryption. It uses a 256-bit key to both encrypt and decrypt data, and the GCM mode provides authenticated encryption — meaning it detects if the ciphertext has been tampered with.
Your passphrase is converted into a 256-bit encryption key using PBKDF2 (Password-Based Key Derivation Function 2) with 100,000 iterations. This deliberate slowness makes brute-force attacks on weak passphrases much harder. A random salt ensures the same passphrase produces different keys each time.
The output contains three parts concatenated and Base64-encoded: the salt (16 bytes), the initialization vector (12 bytes), and the ciphertext. All three are needed for decryption. Everything runs in your browser using the Web Crypto API — the same cryptographic library used by banks and password managers. No data is ever sent to a server.
This tool in other languages:
Français:
Chiffreur de texte AES-256
Español:
Encriptador de texto AES-256
Deutsch:
Text-Verschlüsselung AES-256
Português:
Criptografador de texto AES-256
日本語:
テキスト暗号化ツール
中文:
文本加密工具 AES-256
한국어:
텍스트 암호화 도구
العربية:
أداة تشفير النصوص AES-256
Paste your text, enter a passphrase, and click Encrypt. The tool uses AES-256-GCM (an authenticated encryption standard) via the browser's Web Crypto API. Copy the encrypted output and share the passphrase through a separate channel to whoever needs to decrypt.
AES-256-GCM — the same algorithm used by TLS, disk encryption, and most modern secure applications. The passphrase is converted to a 256-bit key via PBKDF2 with a random salt. GCM mode provides both confidentiality and authentication, so tampering with the ciphertext is detectable.
The cryptography is industry-standard. The weakest link is the passphrase — a short or guessable passphrase breaks everything. Use a long, random passphrase (16+ characters) and share it through a different channel than the ciphertext. For routine communication, use a proper end-to-end app (Signal, iMessage) — they handle key exchange automatically.
The recipient opens this tool, pastes the encrypted output, enters the same passphrase, and clicks Decrypt. If the passphrase is correct and the ciphertext hasn't been tampered with, the original text appears. Wrong passphrase or altered ciphertext results in an error (no partial decryption).
Not without the passphrase. AES-256 with a strong passphrase is computationally infeasible to break — even state actors can't brute-force it in any practical time. The attacker's best bet is guessing your passphrase (if it's weak) or getting it from you some other way (phishing, shoulder-surfing).