Protect PDF
Add password encryption to a PDF document.
Choose a file or drag it here
Accepts PDF · Up to 25MB
Options
Encrypted upload · Auto-deleted after 1 hour · PDPA compliant
Adding a password to a PDF controls who can open it. Our protect tool applies AES-256 encryption — the same standard used by financial institutions — and returns a locked PDF that requires a password before it can be viewed. Without the correct password the file appears blank or displays an error in any PDF reader.
When PDF password protection is necessary
Legal firms emailing confidential settlement terms, medical professionals sharing patient records to external specialists, HR departments distributing salary slips to employees — all require a mechanism to ensure only the intended recipient can open the document. In Malaysia, protecting PDFs sent over email or WhatsApp is considered a best practice under PDPA data protection obligations, particularly for documents containing IC numbers, bank account details, or health information. Pakistani businesses sharing vendor contracts or financial projections with external parties use password protection to limit access to the intended contact only.
Common Use Cases
HR Salary Slip Distribution
HR departments protecting monthly salary slip PDFs with each employee IC number ensure only the intended recipient can open the document, even if the email is accidentally forwarded.
Legal and Confidential Contracts
Law firms protecting settlement agreements, NDAs, and shareholder documents send the password via a separate channel such as SMS, keeping the delivery mechanism separate from the document.
Medical Records and Referral Letters
Clinics sharing patient referral letters with external specialists protect the PDF in compliance with PDPA personal data obligations, ensuring only the authorised receiving practitioner can access the file.
Pre-Investment Financial Reports
Malaysian SMEs sharing financial projections and business valuations with potential investors protect these documents before distribution to maintain strict control over sensitive figures during due diligence.
How to use Protect PDF — step by step
Upload the PDF
Drop the PDF you want to protect. Up to 25 MB is supported.
Enter a password
Type a strong password in the password field. Use a mix of uppercase, lowercase, numbers, and symbols. Minimum 8 characters is recommended.
Download the protected PDF
The encrypted PDF downloads. Test it immediately by opening it in a PDF reader — it should prompt for the password before showing any content.
Tips for best results
Never send the password in the same message as the PDF. Call the recipient or send via a different channel (SMS, WhatsApp, phone call).
Write the password down before you close the tab — there is no recovery mechanism. A lost password means the PDF is permanently inaccessible.
Longer passphrases (three or more random words together) are more secure and easier to communicate verbally than complex short passwords.
If the recipient uses an older PDF reader, verify they can open AES-256 encrypted files — readers older than Adobe Reader 9 may not support AES-256.
Frequently Asked Questions
What encryption strength is used?
AES-256 encryption, which is compliant with current security standards and used by banks and government agencies worldwide. Brute-force attacks on AES-256 are computationally infeasible with modern hardware.
Can I restrict editing or printing without setting an open password?
This tool sets an open password (required to view the file). Owner-level restrictions (preventing editing, copying, and printing without preventing viewing) are a separate PDF permission feature not available in this tool.
Will the protected PDF maintain all its original content and formatting?
Yes. Password protection only adds an encryption layer — it does not alter content, fonts, images, page layout, or interactive elements like form fields.
Can I protect a PDF that is already password-protected?
No. Unlock the PDF first using our Unlock PDF tool, then re-protect it with your new password.
Does AES-256 protection work on iPhone and Android?
Yes. Modern mobile PDF readers including Adobe Acrobat Mobile, Samsung's built-in reader, and iOS Preview all support AES-256 encrypted PDFs.
Free
Always free
0
Accounts needed
1hr
File retention
SSL
Encrypted