What does Protect PDF do?
Protect PDF is a free online tool that can encrypt PDF with a password. The PDF result from Protect PDF is a separate copy to inspect before you use it elsewhere. One possible use is private copies protected before limited sharing.
Password protection encrypts a PDF with the password you supply. This tool uses qpdf with 256-bit encryption and supplies the same password as both the user and owner password.
It is useful when access to a shared copy should require a password. Choose a strong password and pass it to the reader through an right separate channel.
Adding encryption cannot control what an authorized reader does after opening the file. Use a password that you can store safely.
The recipient needs both the file and the password to open it. Keep those deliveries separate where your workflow allows.
A weak password can still be guessed. After a reader opens the file, encryption does not stop them from making another copy.
Encrypt a PDF with a password online: steps
Before using Protect PDF, decide what the new copy must contain and where it will be used. Choose and safely record the password before sending, since this service is not a password-recovery system. Review the upload area and all values required by the current Protect PDF form.
Choose the source
Test the opening password in the recipient's usual PDF reader. For Protect PDF, choose one source from your device. Keep a source copy for another attempt.
Review the form values
Password controls a value used by Protect PDF. Enter your chosen Password value.
Run the file task
Use Process Protect PDF after checking the source and form values. Wait for the job to finish. An error means this attempt failed.
Save and check the output
Open the result in a PDF reader and check that the planned password is required and works. Store the output on your device. Name this copy separately from the original.
Encrypt PDF: uses for Protect PDF
Protect PDF can help with records encrypted for an approved reader. It can also be used for drafts distributed with a separate password channel. The PDF result from Protect PDF must suit the intended reading or editing step, so keep the source until that check is complete.
- Private copies protected before limited sharing.
- Records encrypted for an approved reader.
- Drafts distributed with a separate password channel.
- PDFs tested for format support with a password-aware reader.
Formats and limits for Protect PDF
The Protect PDF form accepts PDF sources. Each Protect PDF upload can be up to 300 MB, which equals 300 MiB. The allowed suffixes on the Protect PDF page do not prove that a source has valid content inside it.
| Accepted formats | Maximum file size | Output |
|---|---|---|
| 300 MB per file (300 MiB upload limit) |
A password limits who can open the file. This form has no separate menu for print or edit rights.
How this tool works
Protect PDF uses qpdf to handle the source on the server. The Protect PDF request uses your chosen input rather than any local editing project left on your device. Check the PDF contents produced by Protect PDF before treating them as ready for another app or reader.
For Protect PDF, your browser uploads the source to our file-processing server. This is a server task, not local editing.
Files are due for deletion within 1 hour. Cleanup runs during normal service operation. Keep a local download for future use.
Protect PDF questions and answers
If Protect PDF gives an unexpected result, start by checking the source type and the values used in the form. Check the PDF contents from Protect PDF as well as the filename or displayed message. For another result type, compare Protect PDF with the separate tools described in these answers.
What matters when using Protect PDF?
Keep the password out of the message carrying the file. View that area at its intended display size. Note any differences that affect your purpose.
Why try Unlock PDF?
Unlock PDF offers another task beside Protect PDF: remove password encryption from a PDF. Unlock PDF returns PDF. The stated PDF output from Protect PDF matches a listed input type for Unlock PDF.
Why try Remove PDF Metadata?
Remove PDF Metadata offers another task beside Protect PDF: remove PDF metadata tags with ExifTool. Remove PDF Metadata returns PDF. The stated PDF output from Protect PDF matches a listed input type for Remove PDF Metadata.
Why try Add Watermark PDF?
Add Watermark PDF offers another task beside Protect PDF: overlay watermark text on every page of a PDF. Add Watermark PDF returns PDF. The stated PDF output from Protect PDF matches a listed input type for Add Watermark PDF.
What if my PDF result does not open?
For a failed Protect PDF result, first confirm that the download completed and that the viewer supports PDF. Try another local viewer for that format.
Record any error message for support. Keep private source material out of the report.
How do I report a problem with Protect PDF?
Contact support with the Protect PDF page name, source format and the error you saw. Mention any relevant form settings you chose. Do not send passwords or private attachments.