Protect PDF with a Password
Share tool
Only this public address is included. Your files, inputs and results stay out of the link.
Add a password required to open your PDF. Create an AES-256 encrypted copy locally and choose optional reader permissions for printing, editing or copying.
Preparing your tool…
How to use it
- Choose an unencrypted PDF or load the synthetic example.
- Set a strong opening password and enter it again. Keep it separately: this tool does not provide password recovery.
- Optionally enter a distinct owner password and choose reader permissions for printing, editing and copying. These permission flags do not provide the same protection as the opening password.
- Create the protected PDF. Review the checked temporary clear preview and download protected.pdf; the downloaded file remains encrypted.
- Open the saved PDF in your reader: a missing or incorrect opening password must fail, and the correct password must show the intended pages. Reset clears the current tool state.
Protect the synthetic four-page source with a new opening password. Reopening without that password must fail; entering it must preserve text, vector shapes, page rotation and cropping. A fresh export uses fresh cryptographic randomness.
Details & limits
Up to 25 MiB input/output and 100 pages; 60 seconds per operation. Signed PDFs, XFA, embedded files and active document actions are rejected. Checked JPEG and unfiltered/Flate images are supported within decoded-resource limits; inline images, JPEG 2000, JBIG2 and CCITT are unsupported. No PDF/A, PDF/UA or signature-validity certification. Passwords must contain 1–127 UTF-8 bytes and no line breaks or NUL. qpdf 12.4.1 loads about 2.25 MB on use; its WASM memory is capped at 512 MiB, excluding other browser memory. Already encrypted input must first be unlocked. Optional print/change/copy permissions rely on reader support. If no owner password is supplied, a separate random one is generated for this export.
Do copying restrictions prevent every recipient from copying the contents?
No. AES-256 encryption controls opening with a password. Print, edit and copy restrictions are advisory flags that PDF readers may ignore once the document is open. A weak or shared password can weaken practical protection. The preview is intentionally decrypted in temporary local memory for checking; only the protected PDF is offered as this tool's download.