Protect PDF with a Password
Add password protection to any PDF instantly. Lock your document so only authorised users can open it — free, no sign-up, files deleted after 1 hour.
Drop your PDF here or click to browse
PDF files up to 20MB
The PDF will require this password to open. Keep it safe — there is no recovery option.
How to password protect a PDF online
Upload Your PDF
Drag and drop your PDF into the upload area or click to browse. Files up to 20MB are supported.
Set a Password
Enter the password you want to use. Anyone who opens the PDF will need to enter this password.
Download Protected PDF
Click Protect PDF and your password-locked file downloads instantly. Store your password safely.
Why use TryMyPdf to protect PDFs?
AES Encryption
PDFs are encrypted using AES-128 — the same standard used in secure file formats worldwide.
100% Free
Protect as many PDFs as you need. No account, no subscription, no usage limits.
Files Auto-Deleted
Uploaded files and protected PDFs are permanently deleted from our servers within 1 hour.
Works Everywhere
Protected PDFs open in Adobe Acrobat, browsers, Preview on Mac, and all standard PDF readers.
Frequently Asked Questions
What type of encryption is used?+
TryMyPdf uses AES-128 encryption, which is supported by all modern PDF readers including Adobe Acrobat, Preview on macOS, Chrome, Firefox, and Edge.
Can I recover the password if I forget it?+
No. PDF encryption is one-way — there is no recovery mechanism. If you lose the password, the file cannot be opened. Always store your password in a secure location such as a password manager.
Will the protected PDF work in all PDF readers?+
Yes. The encrypted PDF uses a widely-supported standard. It will prompt for a password when opened in Adobe Acrobat, Apple Preview, browser-based PDF viewers, Foxit, and all major PDF readers.
Can I remove the password later?+
Yes — use our Unlock PDF tool to remove the password from a protected PDF (you will need to know the current password to unlock it).
Is there a file size limit?+
Files up to 20MB can be uploaded. Most PDFs are well within this limit.
Are my documents stored after protection?+
No. All uploaded and processed files are automatically deleted from our servers within 1 hour. We never read or share your documents.
What is Protect PDF?
PDF password protection encrypts a PDF document so that it cannot be opened without entering the correct password. This is different from watermarking — the document contents are mathematically encrypted using AES-128, making them unreadable to anyone without the key. When a user tries to open the protected PDF, their PDF reader will prompt for the password before displaying any content.
When should you use it?
Protect a PDF when you need to share a document with restricted access — contracts sent before signing, payslips sent to employees, confidential reports shared with clients, or any sensitive document sent over email or stored in shared cloud folders where others may have access.
How Protect PDF works under the hood
TryMyPdf uses AES-128 encryption via the @cantoo/pdf-lib library. The PDF is loaded, the encryption dictionary is set with your user password (required to open) and matching owner password, with printing allowed but copying and modifying restricted. The encrypted PDF is returned as a download — your original file and the output are both deleted from the server within one hour.
Common use cases for Protect PDF
Confidential Reports
Send sensitive business reports, financial data, and strategic documents over email with password protection to restrict access.
Payslips & HR Documents
Payroll departments routinely password-protect payslip PDFs before emailing to employees — each person gets their own password.
Legal Contracts
Protect draft contracts before they are signed and finalised to prevent recipients from forwarding unexecuted versions freely.
Medical Records
Patient records and test results sent electronically should be protected. A password adds a layer of access control.
Client Deliverables
Agencies and consultants protect project deliverables, proposals, and reports before sharing with clients for review.
Exam Papers
Teachers and training providers protect exam PDFs before distribution to prevent early access by unauthorised students.
Tips for best results
Use a strong, unique password
Avoid short or common passwords like '1234' or 'password'. A strong password is at least 10 characters with a mix of letters, numbers, and symbols.
Store your password securely
There is no password recovery for encrypted PDFs. Store the password in a password manager (like Bitwarden, 1Password, or your browser's built-in manager) immediately after protecting the file.
Send the password separately
Never send the password in the same email as the protected PDF. Use a different channel — a text message, phone call, or separate email — so that intercepting one message is not enough to access the document.