Password-protect your PDF files online for free with AES-128 encryption. Set a user password, confirm it for accuracy, and download a secure PDF. 100% free, no uploads, fully private. Best free online PDF password protector.
Drop your PDF file here
or
PDF only · Max 200 MB
200 MB
Max file size
Format
100% local
Privacy
~5 seconds
Speed
128-bit AES
Encryption
Free forever
Price
Combine multiple PDF files into a single document online. Merge PDFs in any order, rotate individual pages, and download the combined result — all processed locally in your browser.
Split PDF files into multiple documents online. Extract specific pages by range, split into chunks of N pages each, or export every page as a separate PDF. All processed locally in your browser.
Rearrange, rotate, and delete pages in your PDF files online. Reorder pages by drag-and-drop, rotate individual pages, remove unwanted pages, and download a perfectly organized PDF — all processed locally in your browser.
Crop PDF pages by removing unwanted margins. Drag the crop handles to select the visible area, choose from preset aspect ratios, and apply to all or specific pages — all processed locally in your browser.
Delete unwanted pages from your PDF files online. Select pages to remove from a visual thumbnail grid, keep only the pages you need, and download a clean PDF — all processed locally in your browser.
Rotate individual PDF pages or all pages at once. Clockwise 90°, counter-clockwise 90°, or 180° rotation. Visual thumbnail grid, batch rotate all, reset all — all processed locally in your browser.
Password protecting your PDF documents is essential for controlling access to sensitive information — whether you are sharing confidential business reports, personal financial documents, legal contracts, or private client data. The Protect PDF tool lets you add strong password protection to any PDF file using AES-128 encryption, all directly in your browser with no file uploads to any server.
Simply upload your PDF, enter a password (minimum 4 characters), confirm it for accuracy, and download a securely encrypted copy. The protected PDF will require the password to open in any PDF reader — Adobe Acrobat, browser PDF viewers, mobile PDF apps, and more. A visual confirmation checkmark shows when your passwords match, and a clear warning reminds you that the password cannot be recovered if lost.
All processing runs entirely in your browser using pdf-lib for professional-grade PDF encryption. Your files are never uploaded to any server — complete privacy for sensitive documents. The responsive layout works seamlessly across phones, tablets, and desktops, making it easy to protect PDFs on any device.
Tip: Use a strong password with a mix of uppercase letters, lowercase letters, numbers, and special characters (e.g., "MySecureDoc!2024"). Avoid using obvious passwords like "password" or "1234" that are easy to guess.
Input: "confidential-report.pdf" (25 pages, 6.8 MB)
Situation: A confidential quarterly business report containing financial data and client information. The report must be shared with your management team via email, but it should not be accessible if the email is intercepted or forwarded to unauthorized recipients.
Step 1 - Upload: Drop confidential-report.pdf onto the upload area. The file info bar confirms the document name, size, and that it contains 25 pages.
Step 2 - Set password: Type "Q4-FY2024-Report!" in the Password field. The show/hide toggle lets you verify the text. Re-type the same password in the Confirm Password field. A green checkmark and matching border appear, confirming the passwords are identical.
Step 3 - Process: Click the floating Protect PDF button. The spinner appears and completes in approximately 5 seconds.
Output: "confidential-report-protected.pdf" — all 25 pages are encrypted with AES-128 encryption. Opening the PDF prompts for the password "Q4-FY2024-Report!". The file is secure for email distribution, cloud storage, or any other sharing method.
Alternative: For client contract documents, use a unique password per client (e.g., "Client-Acme-2024"). Share the password through a separate communication channel (phone call or separate email) for enhanced security.
The tool uses AES-128 encryption, which is the standard PDF encryption method supported by Adobe Acrobat, browser PDF viewers, mobile PDF apps, and virtually all PDF reader software. AES-128 provides strong protection for your documents.
This tool sets both the user password (required to open the PDF) and the owner password (required to change permissions) to the same value. This means anyone who knows the password can both open the file and modify permissions. For most use cases, this provides the right balance of security and convenience.
The password cannot be recovered. If you lose the password, you will not be able to open the protected PDF. We strongly recommend storing your password in a secure password manager or sharing it through a separate communication channel from the PDF itself.
This tool only adds password protection. To remove password protection, you would need to open the PDF with the password in a PDF editor like Adobe Acrobat and save a copy without the password, or use a dedicated PDF unlocker tool.
The maximum file upload size is 50 MB. If your file exceeds this limit, you will see a clear error message explaining the constraint. For larger files, consider using our PDF Compressor tool first to reduce the file size.
No. The tool cannot process PDFs that already have password protection. If your PDF is already encrypted, you must remove the existing password protection first using a PDF unlocker tool before re-protecting it with a new password.
Absolutely. All processing happens entirely in your browser using client-side JavaScript. Your PDF files and passwords are never uploaded to any server. The tool uses pdf-lib running locally in your browser to read, encrypt, and save your documents. Your data never leaves your device.
Yes, the tool is fully responsive and works on any modern mobile browser. All form controls are touch-friendly with clear labels and validation feedback, and the layout adapts seamlessly from phones to tablets to desktops.
No. Your original PDF file is never modified. The tool reads the file, applies AES-128 encryption with your password, and creates a new securely encrypted copy. You download the new file — your original remains completely untouched on your device.
The tool displays a 5-second processing spinner to provide consistent visual feedback. Actual encryption completes very quickly — typically under a second for most documents. The spinner ensures you see a clear transition from input to output.
Yes, the Protect PDF tool is completely free with no hidden costs, subscriptions, or premium tiers. No watermarks, usage limits, or registration required. Protect as many PDFs as you need.
Yes, the tool works with any PDF including scanned documents. The encryption is applied to the entire PDF file regardless of its content type — text, images, or scanned pages are all protected equally.
No. AES-128 encryption does not affect the visual quality or content of your PDF. The encryption only adds password-based access control — every page, image, and font remains exactly as it was in the original file.
For maximum security, use a password that is at least 8–12 characters long with a mix of uppercase letters, lowercase letters, numbers, and special characters. Avoid dictionary words, personal information, or common phrases. Use a password manager to generate and store strong passwords (e.g., "gT7#kL9$mN2@qR5").
