Encrypt or decrypt a file with a passphrase
Wrap any file in AES-256-GCM encryption with a passphrase. The same passphrase decrypts it later, only on this site.
Drop your file here
or click to browse
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Check it yourself: open your browser’s developer tools, go to the Network tab, and run the tool. Or turn off Wi-Fi once the tool has loaded; it keeps working.
How it works
Wrap any file in AES-256-GCM encryption with a passphrase. The same passphrase decrypts it later, only on this site.
Drop a file and choose Encrypt mode. The tool generates a random 16-byte salt and 12-byte IV, derives a key from your passphrase via PBKDF2-SHA256 (600,000 iterations), and encrypts the file with AES-256-GCM via the Web Crypto API. Output is a binary file with extension .lockedfile that bundles a 4-byte magic header, the salt, the IV, and the ciphertext. To decrypt, drop the .lockedfile back in, type the same passphrase, and pick Decrypt (auto-selected for .lockedfile files). The original is reconstructed exactly. The passphrase never leaves your device, there's no recovery if you forget it. The format is custom to this site (the LCL2 header), so other tools won't decrypt it without knowing the layout. For sharing with someone else, they need to open the same site and use the same passphrase you set.
How to use it
- Drop your file. Any file works; choose Encrypt mode.
- Set a passphrase. Pick one you'll remember — there is no recovery if you forget it.
- Encrypt and download. The tool derives a key via PBKDF2 and outputs an AES-256-GCM encrypted .lockedfile.
- Decrypt later on this site. Drop the .lockedfile back in with the same passphrase to restore the exact original.
Frequently asked questions
- What encryption is used?
- AES-256-GCM with PBKDF2-SHA256 key derivation (600,000 iterations) and a random salt and IV per file. All via Web Crypto.
- Can someone decrypt my file with another tool?
- Only if they replicate this site's format (LCL2 header + salt + IV + ciphertext) and use your passphrase. Standard tools won't recognize the wrapper.
- What if I forget the passphrase?
- The file is unrecoverable. There's no backdoor, no key recovery. Use a passphrase you'll remember or write down safely.
- Is my file uploaded?
- No. The whole encrypt / decrypt cycle runs in your browser. Your passphrase never leaves the device.