File Encryptor & Decryptor (AES-256-GCM)
Encrypts files such as images, PDFs, and documents with a password and saves them as .enc files. Decryption works on the same page. It uses the browser built-in Web Crypto API and everything stays in your browser. Your files and password are never sent to a server. To encrypt plain text instead, use the Text Encryptor & Decryptor.
🔒 Runs in your browser · Your data is never sent to a server
Drag & drop a file here, or choose one (up to 512 MB)
How to use
- Choose the Encrypt or Decrypt mode.
- Drag and drop a file into the box, or choose one.
- Enter a password and press Encrypt or Decrypt.
- When it finishes, press Download to save the result. Encrypting adds .enc to the original file name.
Notes
- If you forget the password, the file cannot be decrypted. There is no way to reset or recover it.
- The strength of the encryption depends on the password. Avoid short or guessable passwords.
- Both the input and the output are held in browser memory, so files are limited to 512 MB. Very large files may fail if the browser runs out of memory.
- The file name and type (MIME type) are also encrypted inside the .enc file and restored on decryption. The encrypted file size still reveals roughly how large the original was.
- The format is specific to this tool. Files encrypted with OpenSSL or other tools cannot be decrypted here, and .enc files from this tool cannot be opened elsewhere.
- The file is encrypted in 1 MB blocks, and the order of the blocks and the final block are authenticated. A truncated or modified file makes decryption fail.
Glossary
AES-256-GCM
A symmetric cipher with a 256-bit key. GCM mode attaches an authentication tag while encrypting, so decryption fails if the ciphertext has been modified.
PBKDF2
A way to derive an encryption key from a password. Repeating the computation hundreds of thousands of times slows down brute-force password guessing.
Chunked encryption
Splitting a large file into 1 MB pieces and encrypting them one by one. It keeps memory use low and lets each piece, its order, and the presence of the final piece be verified.
FAQ
Is my file uploaded to a server?
No. The file is encrypted and decrypted inside your browser and is never sent anywhere. It works even when you are offline.
Can I open the encrypted file with other software?
No. The format is specific to this tool, so it can only be decrypted here. Files made with OpenSSL, 7-Zip, or other tools cannot be decrypted here either.
How large a file can I encrypt?
Up to 512 MB per file. Both the input and the output are held in browser memory, so larger files are not supported. On devices with little memory, smaller files may also fail.
Why do I get "Could not decrypt" or "ends too early"?
A wrong password cannot decrypt the file. If the end of the file is missing it is reported as truncated, and if part of it was changed it is reported as altered or corrupted. Check that the download finished.
Are the original file name and extension restored?
Yes. The name and type are stored inside the ciphertext, so decrypting offers the file under its original name. The encrypted file itself is named "original-name.enc".
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