MyPassGen
Online file encryption
Encrypt or decrypt a file in the browser with AES-256-GCM. Up to 5 GB. Output .lock / .enc. The file and passphrase are not uploaded.
How to encrypt a backup file locally
Before a certificate bundle, exported spreadsheet, or config with keys lands in cloud storage, people search “online file encryption.” If the tool uploads the file and encrypts it on a server, the plaintext window gets larger. This page uses Web Crypto for streaming AES-256-GCM in the browser, then downloads the result.
The passphrase is derived with PBKDF2 (100,000 iterations, SHA-256). One file, up to 5 GB. The same page can encrypt a block of text. To decrypt, drop the .lock / .enc file back in and enter the original passphrase to restore the name and contents.
- The file and passphrase are not uploaded as business data. Keep the download yourself
- A forgotten passphrase cannot be recovered. Use the online password generator for a long enough passphrase
- Short secrets (passwords, recovery codes) fit a burn-after-read link better than a whole-file flow
FAQ
Does online file encryption upload the file?
No. Encryption and decryption run in the browser. The file and passphrase are not uploaded as business data. The result downloads as .lock or .enc. Store it where you trust.
Which algorithm, and how large can a file be?
AES-256-GCM authenticated encryption. The passphrase is derived with PBKDF2 (100,000 iterations, SHA-256). One file, up to 5 GB, processed in chunks. You can also encrypt a block of text on this page.
Can I decrypt if I forget the passphrase?
No. There is no server-side plaintext or passphrase backup. Use a long passphrase and keep it in your own password manager.
How do I send an encrypted file to someone else?
Send the .lock / .enc file by drive or email, and the passphrase on a different channel. Short secrets fit a burn-after-read link. This tool is for local backups and whole-file encryption.