File Encryptor

Encrypt any file with AES-GCM and a passphrase, then decrypt it again in the same page.

Encrypt or decrypt a file

Mode

Choose a file and type a passphrase.

No file has been processed yet.

The output starts with a header holding the magic bytes, the iteration count, the random salt and the IV, so decryption can read them back.

Choose the file you want to protect and type a strong passphrase.
Click Run in encrypt mode and download the encrypted result.
Pick decrypt mode later, choose the encrypted file and enter the same passphrase.

Common questions about the free online file encryptor.

It derives a 256-bit key from your passphrase with PBKDF2 and a random salt, then encrypts the file with AES-GCM and a random IV.

The first 39 bytes hold the magic bytes, a version number, the iteration count, the 16 byte salt and the 12 byte IV, followed by the ciphertext.

They make every encryption different even for the same file and passphrase, so attackers cannot spot repeated content or reuse old results.

No. The file never leaves your device. Everything is read and encrypted locally in your browser, and nothing is stored anywhere.

Yes. Open this page, switch to decrypt mode, choose the encrypted file and type the same passphrase. The header supplies the salt and IV.

The file cannot be recovered. There is no backdoor and no reset, because the key exists only while you type the passphrase.

Use a long phrase of several random words. Length matters most, since PBKDF2 slows guessing but cannot rescue a short and obvious passphrase.

Yes, but very large files are limited by the memory of your device, because the whole file is held in the browser while it is encrypted.

Yes. The tool is completely free, needs no account, and you can encrypt or decrypt as many files as you like.

Last updated: October 10, 2026