Cryptography Tools
AES-GCM Encrypt / Decrypt
Encrypt text with AES-256-GCM using a password-derived key, or decrypt an envelope produced by this tool. All work runs in the browser.
✓ Every tool runs in your browser. We do not upload your input or output.
Keyboard shortcuts
Ctrl/⌘ + Enter: process
Ctrl/⌘ + Shift + F: full screen
Esc: exit full screen
Ctrl/⌘ + F in editor: search
How to use
- Choose Encrypt, enter plaintext, and type a strong password.
- Run the tool, then save the full JSON envelope containing salt, IV, and ciphertext.
- For decryption, choose Decrypt and paste that complete envelope.
- Enter the same password and run the tool to recover the text.
Examples
Protect a small deployment note
The envelope can be copied or downloaded; the password must be stored separately.
Deployment note: rotate the staging token.
A JSON envelope with v, kdf, iter, salt, iv, and data
Understand the saved envelope
Encryption creates a fresh random salt and IV for each operation. The browser derives a 256-bit AES key from your password using PBKDF2 with SHA-256 and stores the derivation settings alongside the ciphertext in a JSON envelope. AES-GCM authenticates the ciphertext, so edits and wrong passwords cause decryption to fail. Save the entire envelope rather than copying only the data field. The salt and IV are not passwords; they are needed to recreate the key and decrypt the message.
Use a long, unique password and keep it apart from the encrypted output. This tool is intended for small text messages and compatibility with its own format. It does not manage keys, provide collaboration, or replace a dedicated secrets manager. Content and password are processed in a local browser worker and are not uploaded to the site.
Frequently asked questions
Can I decrypt output from another AES website?
Only if it uses this envelope format and the same PBKDF2 and AES-GCM settings.
Does a wrong password return partial text?
No. AES-GCM authentication fails and the tool reports a decryption error.
Where is my password sent?
Nowhere outside this tab. It is used by browser cryptography and is not stored by the site.
Can I recover a lost password?
No. Keep your password safely; the site does not have a recovery service.