Protect PDF
PopularEncrypt with a password.
Protect PDF runs on our secure server
Anyone opening the PDF will need this password. Store it somewhere safe — it can't be recovered.
Strongest. AES-256 encryption (PDF 2.0) — best for modern readers.
- Encrypted upload
- Your file is uploaded directly to short-lived object storage over a pre-signed URL.
- Safety checks
- Each file is checked before any processor sees it: an empty file, a file whose type contradicts its name or this tool, or a PDF with no PDF header is refused. Whether a malware scan runs as well is reported by the live server, and shows here once this page has heard from it.
- Processing
- A separate processing server — not this website — fetches your file from that storage and does the work.
- Download
- You get a signed, expiring link to the result — no account required.
- Auto-delete
- Inputs are wiped right after processing; outputs auto-delete within the retention window.
Checking our secure server…
No account required. This runs on a separate processing server, not in your browser: files travel over an encrypted connection, are processed in a temporary per-job folder that is erased when the job ends, and are deleted automatically. Your password is never logged. Our job queue removes it when the job finishes or is cancelled — or, if no server picks it up, when the queue's retention lapses after 24 hours — and the queue's on-disk journal, on our web server, can keep a copy until it is next compacted.
About this tool
Password-protect a PDF with AES encryption, so only people with the password can open it. Encryption runs on an auto-deleting secure server.
Files are processed on a secure server, which deletes the upload when the job ends and serves the result for a limited time.
More details
Protect PDF puts an open password on a document. The result is encrypted with AES, so a PDF reader asks for the password before it will show a single page. Use it when a file travels by email, a shared drive or a USB stick. The encryption is applied by qpdf, and our server re-inspects its own output: a file that does not come back encrypted fails the job instead of being handed over as if it were protected.
qpdf is a native program, so this tool does not run in your browser. Your PDF is uploaded over TLS to pdf.xyz's secure server, and the password travels with the job request so our server can encrypt that one file. The uploaded input is deleted when the job finishes, the link to the protected copy expires after 60 minutes, and a daily storage rule erases the stored copy after that. The panel holds a single PDF at a time, and the upload is refused above 100 MB.
By default the same password becomes the owner password and every permission stays allowed, so whoever can open the file can also print it and copy its text. Under Permissions, you can untick printing, copying text and images, changing the document, adding comments and annotations, filling in forms or inserting, rotating or deleting pages; the panel then asks for a separate owner password, and our server reads the finished file's permission flags back and fails the job if one does not match what you chose. Filling in forms can be blocked only once comments are: allowed while comments are allowed: the PDF format lets anyone who may comment also fill in forms. Text extraction for accessibility is always allowed: AES encryption, the only kind Protect PDF uses, cannot block screen readers from extracting text. A PDF that is already encrypted is refused rather than wrapped twice.
When to use it
Email a payslip or tax return to an accountant
Attach the protected copy and send the password by a different route, such as a text message or a phone call, so one intercepted email does not expose both.
Share a draft contract through a cloud link
Anyone who opens a forwarded link meets the password prompt instead of the clauses, so pick a password that is hard to guess.
Send to someone on older PDF software
If an older reader on the other end cannot open the AES-256 copy, run the unprotected original through again and pick AES-128 under Encryption strength. It is still AES, just a shorter key.
Lock a document after removing sensitive details
Run Redact PDF first to remove account numbers no reader should see, then protect the redacted copy.
How it works
1Add one PDF
Drop a single PDF on the area labelled Add a PDF to password-protect, or browse for one. A Remove button beside the file name lets you swap it.
2Type the new password
Enter it in the New password field. It is masked; the eye button reveals it so you can check for typos. It can be up to 127 bytes long.
3Choose the encryption strength
Under Encryption strength, AES-256 is preselected. Switch to AES-128 only if the recipient's PDF software is old.
4Optional: restrict permissions
Under Permissions, every box starts ticked. Untick what readers may not do, then type an Owner password that differs from the open password; it is the one that lifts the restrictions later.
5Encrypt and download
Press Encrypt PDF once a file and a password are both in place. When "Your PDF is protected and ready." appears, use the button beneath it; for contract.pdf it reads Download contract-protected.pdf. Open the saved file once to confirm it asks for the password.
Common questions
Should I pick AES-256 or AES-128?
AES-256 is the default and the stronger key; it uses the PDF 2.0 encryption scheme. AES-128 is also AES, never the older RC4 cipher, and is offered for readers that cannot open AES-256 files. Neither choice changes the pages themselves.
Can I stop people printing or copying text from the PDF?
Yes. Untick “Printing” or “Copying text and images” under Permissions and set an owner password that differs from the open password. These are permission flags in the encrypted file. PDF readers that follow the standard honour them, but some software ignores them, and anyone with the owner password can remove them. If a passage must not be readable at all, remove it with Redact PDF before protecting.
How do I change the password on a PDF that is already protected?
An encrypted input is refused with a note to unlock it first. Run Unlock PDF with the current password, then protect that copy with the new one. A PDF that opens without a prompt but carries printing or copying restrictions is encrypted too, so it is refused as well.
What if I forget the password?
pdf.xyz cannot recover it: Unlock PDF removes a password you can type and never guesses one. Keep the unprotected original, or store the password in a password manager.
What happens to my file and password on our secure server?
Both reach our server over TLS, because qpdf needs the password to encrypt. The password sits in the job's queue record, which is deleted when the job ends, and reaches qpdf through a temporary argument file in a scratch folder that is removed after the run. It never appears in the output name or an error message. The input file is deleted when the job ends; the protected copy can be downloaded for 60 minutes, then a daily storage rule erases it. No account is needed.
Are there rules for the password itself?
It cannot be empty, cannot contain control characters such as tabs or line breaks, and cannot exceed 127 bytes. Accented and non-Latin characters take more than one byte each, so the hint under the field counts bytes once you pass the limit.
How large can my file be?
Up to 100 MB per file.
Which encryption does Protect PDF use?
AES only — the older RC4 cipher is never used. Strongest. AES-256 encryption (PDF 2.0) — best for modern readers. Compatible. AES-128 encryption — opens in a wider range of older readers. AES-256 is the default. The password you set is the one needed to open the file.
Can Protect PDF protect a PDF that already has a password?
No — it is turned away rather than encrypted twice. That includes a PDF that opens without a password but has its printing, copying or editing locked by an owner (permissions) password. Remove the current password with Unlock PDF first — the one that opens the file, or that owner password — then protect the unlocked copy.
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No sign-up required. Your files stay on your device until you run a tool.