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Text Encrypt / Decrypt Tool

Encrypt and decrypt text with a passphrase using AES-GCM. Everything runs in your browser — neither your key nor your text is ever sent to a server.

Last updated: 2026/10/16 Developer Feedback & bug reports
This tool runs entirely in your browser. Your text, passphrase, and the encrypted/decrypted results are never sent to or stored on any server.

How to Use

1

Enter Text and Passphrase

On the "Encrypt" tab, enter the text to encrypt and a passphrase. The passphrase is required for decryption, so keep it safe.

2

Run Encryption

Press "Encrypt" to generate a Base64 string encrypted with AES-GCM. Use the copy button to save the result.

3

Decrypt

On the "Decrypt" tab, paste the ciphertext, enter the same passphrase, and press "Decrypt" to recover the original text.

About the Text Encrypt / Decrypt Tool

An online tool that encrypts and decrypts text with AES-GCM using your passphrase as the key. It uses the browser-native Web Crypto API (crypto.subtle) and derives the key securely with PBKDF2. The output is a single Base64 string combining the salt, initialization vector (IV), and ciphertext; the same passphrase is required to decrypt it. Everything runs on your device with no external libraries.

Features

  • AES-GCM 256-bitUses authenticated encryption (AES-GCM) that detects tampering while keeping your data confidential.
  • PBKDF2 Key DerivationDerives the key from your passphrase with PBKDF2 (SHA-256, high iteration count) and a random salt to resist rainbow-table attacks.
  • Fully In-BrowserNeither key nor text is sent to a server. All processing uses the Web Crypto API on your device, with no external libraries.
  • Portable Base64Salt, IV, and ciphertext are packed into one Base64 string you can paste straight into an email or note.

Use Cases

  • Encrypt notes or passwords before storing them in cloud notes
  • Share confidential text securely over email or chat
  • Back up API keys and connection details in encrypted form
  • Keep diaries or drafts in a form only you can read
  • Learn and verify how AES and PBKDF2 encryption work

FAQ

Are my text and passphrase sent to a server?
No. All encryption and decryption happen inside your browser via the Web Crypto API. Your text, passphrase, and ciphertext are never sent to or stored on any server.
What encryption method does it use?
It uses AES-GCM (256-bit) authenticated encryption. The key is derived from your passphrase with PBKDF2 (SHA-256, high iteration count) using a random salt.
Can I decrypt if I forget the passphrase?
No. By design, encrypted data cannot be recovered without the passphrase. This is correct security behavior, and even we cannot restore it. Always store your passphrase safely.
What is inside the Base64 ciphertext?
It is a Base64 encoding of a version marker, salt, initialization vector (IV), and the encrypted data combined together. The same passphrase is required to decrypt it, and the Base64 string alone reveals nothing.
Can it decrypt ciphertext made by other tools?
No. This tool uses its own format (version + salt + IV + ciphertext), so it is designed to decrypt text that was encrypted with this same tool. Interoperability with other tools is not guaranteed.
Can I use it on a smartphone?
Yes. It works in any modern smartphone, tablet, or PC browser that supports the Web Crypto API.

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