Decrypt and restore password-protected files
Unlock encrypted .fz container files using your password. Decryption executes 100% client-side in your browser — your data is never uploaded.
How it works
Upload .fz container
Select the encrypted .fz file created with Filezaar's Encrypt File tool.
Enter your password
Type the password used during encryption to unlock the AES-256-GCM container.
Decrypt locally
Click Decrypt File. The Web Cryptography API verifies integrity and decrypts data.
It is processed on your machine
This is the kind of content people are most nervous about pasting into a website. Here nothing is transmitted: your browser reads the input, the tool works on it in the tab, and the result is handed straight back. Close the tab and it is gone.
- Opened from your disk by your browser — not sent anywhere first.
- Held in the tab while the tool works, then dropped.
- Saved to your device by your browser, not by a link to a server.
- Closing the tab clears the working copy completely.
- No account, so nothing is ever attached to an identity.
- No tracking of what you worked on or what was inside the file.
There is no queue and no retention policy to read. Whatever you pasted is released the moment the tab closes. See how your data stays inside the tab for the full picture, or follow the DevTools check to verify your file never leaves.
What people use it for
Formats & limits
What this tool accepts, what it produces, and what it will never ask you for.
- Input
- Encrypted .fz container files
- Output
- Set in the controls above
- Maximum file size
- Set by your device, not by a plan
- Files per run
- One at a time
- Sign-up required
- None
- Watermark
- Never added
- Works offline
- Yes, once the page has loaded
- Supported browsers
- Any current Chrome, Edge, Firefox or Safari
When something goes wrong
Invalid input stops with a plain message that points at the exact problem, rather than a spinner that never finishes.
The content is not in the shape this tool expects. Check for a missing bracket or an extra character and try again.
Why not an online service
A hosted version of this tool means your input is transmitted to a server you have no relationship with. Removing that step removes the whole category of risk.
A typical upload site
This tool
Questions
Is my encrypted file uploaded?
No. Decryption is performed entirely inside your web browser. No keys, passwords, or decrypted data are ever sent over the network.
What happens if I enter the wrong password?
Decryption will fail with a secure error notice: 'Wrong password, or the file is damaged.' The tool does not reveal key hints.
Can this tool decrypt password-protected ZIP or RAR files?
This tool decrypts .fz containers created by Filezaar's Encrypt File tool. For password-protected PDFs, see our Unlock PDF tool.
Can Filezaar help me recover a lost password?
No. Filezaar has zero access to your password or data. Without the correct password, AES-256-GCM encryption cannot be decrypted.
Is there a file size limit?
No fixed limit is imposed by the tool. The practical ceiling is how much memory your device has free, because the whole job runs inside this browser tab.
Does it work without an internet connection?
Yes, once the page has loaded. Nothing is fetched while you work, so a dropped connection does not interrupt a run.