[ENCRYPT FILE ONLINE]

Strong file encryption in your browser — your file never touches a server.

Pick a file, choose a password or generate a random 256-bit key, and download an encrypted .enc file you can safely email, back up, or drop in cloud storage. The encryption runs locally in your browser, so the file itself is never transmitted anywhere.

Nothing here is a trial or a teaser: no account, no watermark, no size cap, and no upper limit on how many files you encrypt.

ENCRYPT_FILE_ONLINE_v1.0.0
🔒 [ENCRYPT] 🔓 [DECRYPT]

[1] SELECT FILE

[2] CHOOSE ENCRYPTION ALGORITHM

[4] ENCRYPT FILE

[CHOOSING BETWEEN A PASSWORD AND A RANDOM KEY]

This is the decision that determines how strong your encryption actually is, and it is worth thirty seconds of thought.

Random 256-bit key — strongest

The tool generates a key with your browser's cryptographic random number generator. It cannot be guessed or brute-forced. The trade-off is that you must store it: put it in a password manager immediately, because losing it means losing the file.

Password — most convenient

Your password is stretched into a key using PBKDF2 with 600,000 iterations, which makes guessing attempts expensive. But the key is only ever as strong as the password behind it: a short or common password can still be brute-forced, no matter how good the cipher is. Use a long passphrase, or the built-in generator.

Your own key — for existing key management

If you already manage 256-bit keys, paste one in hex or base64. Useful when the key comes from elsewhere in your infrastructure.

[AES-256 OR CHACHA20-POLY1305?]

Both are modern, well-analysed ciphers with no practical attacks against them. The honest answer is that either is fine, and the difference is performance, not security.

  • AES-256 — the default. Almost every modern CPU has dedicated AES instructions, so on a desktop or laptop it is typically the faster of the two. It is the standard used by governments, banks and enterprise storage systems.
  • ChaCha20-Poly1305 — designed by Daniel J. Bernstein and standardised in RFC 8439. It is fast in pure software, which makes it a strong choice on older phones and low-power devices that lack AES hardware acceleration. It is what TLS falls back to on such hardware.

If you have no reason to prefer one, keep the default. A file encrypted with either can be decrypted here later; the algorithm is recorded in the file header.

[WHAT ENCRYPTING A FILE DOES AND DOES NOT PROTECT AGAINST]

Encryption is precise about what it defends. Knowing the boundary keeps you from relying on it for the wrong thing.

It protects: the contents of the file at rest and in transit. Someone who intercepts the encrypted file, or who gets access to the cloud storage or drive holding it, learns nothing about what is inside.

It does not protect: the file on your own machine before or after encryption; the filename, if you share it (the original name is stored inside the encrypted file, so it is protected there, but the .enc filename you choose is not); or anything at all if the key travels alongside the file. Send the key by a different route than the file.

[HOW TO ENCRYPT A FILE ONLINE]

Encrypt any file with AES-256 or ChaCha20-Poly1305 in your browser, without uploading it.

  1. Select your file. Choose a file with the picker or drag it onto the drop zone. Any file type works, and there is no size limit.
  2. Choose an algorithm. Pick AES-256 (fastest on most desktops) or ChaCha20-Poly1305 (strong choice on mobile and older hardware).
  3. Choose how the key is made. Generate a random 256-bit key for maximum strength, enter a password to derive a key with PBKDF2, or paste a key you already have.
  4. Encrypt the file. Click encrypt. The file is processed locally in 2 MB chunks and an HMAC-SHA256 authentication tag is added so tampering can be detected later.
  5. Save the file and the key separately. Download the .enc file and store the key or password in a password manager. Without it the file cannot be recovered by anyone, including us.

[FREQUENTLY ASKED QUESTIONS]

Is online file encryption actually secure?

It depends entirely on where the encryption happens. A service that uploads your file encrypts it on a machine you do not control, which means the operator can see the plaintext. This tool performs the encryption in your browser with the Web Crypto API, so the file never leaves your device and there is nothing for an operator to see.

What file types can I encrypt?

All of them. Encryption operates on raw bytes, so PDFs, Word and Excel files, photos, video, ZIP archives, source code, database dumps and VPN configuration files are all handled the same way. The original filename is preserved inside the encrypted file.

How strong is PBKDF2 with 600,000 iterations?

It meets current OWASP guidance for PBKDF2-HMAC-SHA256 and is the same order of magnitude used by major password managers. Each guess an attacker makes costs 600,000 hash operations, which turns a fast offline attack into a slow one. It does not rescue a weak password — it buys time proportional to the password's own strength.

Can I encrypt multiple files at once?

Yes. Select several files and they are encrypted in a batch, each producing its own .enc file. If you would rather have a single encrypted output, put the files in a ZIP archive first and encrypt the archive.

Should I compress before encrypting?

Compressing first is the correct order, and the tool offers it as an option. Encrypted data is statistically random and does not compress, so compressing afterwards achieves nothing. Compression is only applied when it actually reduces the size.

What happens if I lose the password or key?

The file is permanently unrecoverable. There is no reset link and no master key, because we never receive your key in the first place. This is a deliberate property of the design rather than a missing feature — save the key before you close the page.