Text Encrypter / Decrypter
Encrypt and decrypt text with AES-256-GCM using a passphrase, entirely in your browser. Uses PBKDF2 key derivation. Nothing is uploaded.
Uses the browser's native Web Crypto API (AES-GCM, PBKDF2) — no external libraries.
How to use this tool
- Type or paste the text to encrypt.
- Enter a strong passphrase.
- Click Encrypt; copy or download the encrypted blob. To decrypt, paste the blob, enter the passphrase, and click Decrypt.
Encrypt and decrypt text with AES-256-GCM using a passphrase, entirely in your browser. Uses PBKDF2 key derivation. Nothing is uploaded.
How it works
The Text Encrypter uses AES-256-GCM, a modern authenticated encryption algorithm, to encrypt any text you enter using a passphrase you choose. Decryption requires the same passphrase, so only someone who knows it can read the original text. The entire process runs in your browser using the Web Crypto API; nothing is sent to a server.
The passphrase is converted into a cryptographic key using PBKDF2 (Password-Based Key Derivation Function 2) with a random salt and many iterations. This makes brute-force attacks against weak passphrases substantially harder. A random initialization vector (IV) is generated for each encryption operation, ensuring that encrypting the same text twice produces different ciphertext.
The output is a Base64-encoded string that bundles the salt, IV, and ciphertext together. You can share this string via email, chat, or any text channel — it is safe to transmit because it is unreadable without the passphrase. To decrypt, paste the encrypted string into the tool, enter the passphrase, and click Decrypt.
This tool is suitable for personal, low-to-medium-sensitivity use cases such as storing a private note, sending a secret message to a trusted contact, or protecting a small amount of sensitive text. For high-security or commercial encryption needs, use dedicated software such as GPG or a password manager.
Worked example
Send an encrypted note to a colleague
- Type your private message into the text field.
- Enter a strong passphrase that you will share with your colleague through a separate channel.
- Click 'Encrypt' — the tool outputs a long Base64 string.
- Copy the encrypted string and send it via email or chat.
- Your colleague pastes it into the tool, enters the shared passphrase, and clicks 'Decrypt'.
The recipient sees the original message; anyone else who intercepts the ciphertext cannot read it without the passphrase.
Common mistakes to avoid
- Using a weak or short passphrase — the encryption is only as strong as the passphrase. Use at least 12 random characters or a passphrase of 4+ random words.
- Sending the encrypted text and the passphrase via the same channel (e.g. the same email thread) — this defeats the purpose of encryption.
- Losing the encrypted string before saving the original text and then forgetting the passphrase — always keep a copy of the original in a safe place until you have verified decryption works.
Key terms
- AES-256-GCM
- Advanced Encryption Standard with a 256-bit key in Galois/Counter Mode. GCM provides both encryption and authentication, detecting tampering with the ciphertext.
- PBKDF2
- A key derivation function that applies a hash function many times with a salt to convert a passphrase into a cryptographic key, slowing down brute-force attacks.
- Initialization vector (IV)
- A random value used together with the key to ensure that the same plaintext encrypted twice produces different ciphertext.
Frequently asked questions
- How strong is the encryption?
- AES-256-GCM with 100,000 PBKDF2-SHA256 iterations — the same approach used in professional password managers.
- Can I decrypt on another device?
- Yes — paste the ENC1:… blob, enter the same passphrase, and click Decrypt in any modern browser.