Protect a PDF with a Password
Add an open password to any PDF so that only people who know it can view the document. The file is encrypted with AES, the encryption standard supported by every modern PDF reader — Adobe Acrobat, browsers, and phone apps will ask for the password before showing the content.
The processing happens on our server: your file is uploaded, encrypted and streamed back to you for download. The password is never stored; your files are kept for 48 hours and then deleted automatically — or you can delete them yourself at any time.
Why Use This Tool to Lock PDF Files?
- Strong AES encryption supported by all modern PDF readers
- Protect several PDF files at once with the same password
- The content, layout and quality of the document stay exactly the same
- No installation, sign-up or watermarking of your document
How to Password-Protect a PDF
- Drag and drop your PDF file, or click to select one
- Enter a password twice, then click the "Lock PDF" button
- Your protected PDF downloads automatically once processing finishes
Frequently Asked Questions
Is this PDF protection tool free?
Yes, password-protecting your PDF files is completely free.
How secure is the protection?
The file is encrypted with AES-128. Its security depends mostly on the password: use at least 10 characters mixing upper- and lowercase letters, digits and symbols (up to 32 characters).
Are my file and password kept private?
Files are transferred over an encrypted connection and processed on our server. Uploaded files and results are stored for 48 hours, so you can download the result via its link, and are then deleted automatically. You can delete them yourself at any time with the delete button in the “Your files” list. The password is used only for processing and is never stored.
Is there a file size limit?
Yes, uploaded PDF files must be 1 GB or smaller.