Protect a PDF with a password
Add an open password to a PDF. You type it; we do not store it on the job or in logs. Anyone without the key cannot open the file in a typical viewer.
- No account needed
- Temporary result, expires on its own
- Processed on our servers
The PDF could not be protected
Sending your file
Processing your file
- Uploading to the server
- Processing your file
- Preparing the download
Your PDF is ready
Download it now: the link is temporary and expires without you deleting anything.
How it works
- Select a PDF Choose an unencrypted PDF and a password of 8 to 64 characters.
- Process the PDF Submit the job and wait for processing to finish.
- Download the result Download the protected PDF while retention lasts. Save the password: we cannot recover it.
Protecting a PDF is so a contract or a receipt does not open in any viewer without a key. On ToolZen you type the password (8 to 64 characters, no control characters and no leading hyphen that could look like a flag). The document is encrypted with AES-256.
The key is not stored on the job record. It is used ephemerally during processing and deleted when processing finishes. If you forget the password, there is no way to get it back: ToolZen does not remember it and does not guess it.
One file, 25 MB, guest retention. A PDF that is already encrypted, a corrupt one or one that is not a PDF is rejected or fails. Success is a PDF that asks for a key on open, not DRM and not an electronic signature. It does not stop screenshots or copying the encrypted file elsewhere: it only asks for the key to open it in a typical viewer.
It is not a digital signature, not a certificate and not a visible stamp. If what you want is overlaid text, use watermark. If you want to rotate or crop, do it before encrypting: a PDF that is already protected does not enter the other PDF tools. Related: unlock PDF, if you know the key; merge or compress, on a file that is still open.
Typical mistakes: a key that is too short, control characters, a PDF that already asks for a password, or a file that is only named .pdf. In those cases you will see a rejection or a job failure, not a half-“protected” document. The result expires with temporary retention; there is no library of encrypted files.
Frequently asked questions
Do you store the password?
No. It is used ephemerally during processing and deleted when processing finishes.
What encryption do you use?
AES-256 encryption. It is not DRM and not a digital signature. A viewer will ask for the same key to open it.
Can I protect a PDF that already has a password?
Not in this step. Unlock it first if you know the key, or use an unencrypted file.
What if I forget the password?
There is no recovery. ToolZen does not store the key and does not break protected PDFs.