How to Decrypt an Encrypted File

An encrypted file is unreadable until you unlock it. When you have a file you previously encrypted — or one sent to you along with its password — decryption restores it to its original, usable form. This guide explains how decryption works, what you need to succeed, and the security reasons to do it locally.

What decryption does

Decryption reverses encryption. It takes the scrambled file and the correct password, and reconstructs the original contents exactly — byte for byte. Without the right password, decryption simply fails; there is no partial result and no way around it. The password is the key, in the literal sense.

How to decrypt a file with this tool

1. Open the Decrypt File tool.
2. Load the encrypted file.
3. Enter the password.
4. Download the restored original file.

The decryption happens entirely in your browser — the file is never uploaded. This is important: a decrypted file is your sensitive data in the clear. Doing it locally means that plaintext never travels to a server, so the moment of vulnerability stays on your own device.

What you need to succeed

Decryption is simple but unforgiving:

• The exact password. Encryption has no back door by design. The correct password is the only way in — no recovery, no reset, no bypass.
• The matching method. A file should be decrypted with the same scheme that encrypted it. A file locked with Encrypt File decrypts here; a file encrypted by a different program may need that program.
• The intact file. A corrupted or partially downloaded encrypted file may not decrypt. Make sure you have the complete file.

If decryption fails

The usual causes, in order of likelihood:

• Wrong password — check for typos, caps lock, and extra spaces. This is nearly always the reason.
• Wrong tool — the file was encrypted by different software.
• Corrupted file — it was damaged in transfer or storage.

There is no way to brute-force or recover a genuinely lost password on strong encryption. That security is exactly what made the file worth encrypting.

After decrypting

Once restored, the file is your normal document, image, or archive again. If it was a bundle, Zip Extractor unpacks it. Check what you have with File Inspector if you are unsure of the type.

Related tools

To encrypt a file in the first place, Encrypt File is the counterpart. For password-protected PDFs specifically, Unlock PDF removes a known PDF password.

Common uses

• Open your own encrypted files.
• Access a file sent with its password.
• Restore archived confidential documents.

Privacy and limits

Decryption is fully local — no upload, no file-size cap, nothing stored, offline once loaded. Open the Decrypt File tool to unlock your files.