Password-protect a PDF
Set a password that must be entered to open the document, and choose what readers are allowed to do with it. The encryption happens on your machine, which matters rather a lot here: uploading a file to a website in order to protect it rather defeats the point.
How to do it
- Open the PDF.
- Choose a password to open the document.
- Optionally set permissions such as printing or copying.
- Download the protected file.
Why nothing is uploaded
Most online PDF tools work by sending your file to a server, editing it there, and sending it back. That means contracts, medical records, bank statements and passports all end up on someone else's machine, and you are trusting a privacy policy about what happens next.
This editor does the work in your browser instead. The PDF is read by this tab, rendered with pdf.js and written back out with pdf-lib, both running as ordinary JavaScript on your own device. There is no upload endpoint, because there is no server doing any of this. Once the page has loaded you can disconnect from the network entirely and everything still works.
Questions
- Is my file uploaded?
- No. Everything happens in this browser tab, on your own device. There is no upload endpoint and no server-side processing, so the file never leaves your machine — you can disconnect from the network after the page loads and it still works.
- How strong is the encryption?
- AES-256, the algorithm specified in ISO 32000-2 revision 6. Weak legacy RC4 encryption is refused outright, so a file protected here cannot accidentally end up protected by broken crypto.
- What is the difference between the two passwords?
- The open password is real encryption — without it the file cannot be read at all. The owner password only guards the permission flags, and those flags are a convention that well-behaved readers honour rather than something enforced cryptographically. Treat permissions as a request, not a guarantee.
- Can I remove a password instead?
- Yes. Open the file with its password, turn protection off, and download — the saved copy is unencrypted.
Related tools
- Remove a PDF password — Remove the password from a PDF you can already open, in your browser. Nothing is uploaded.
- Sign a PDF — Draw, type or upload a signature and place it on any page. Runs entirely in your browser, so the document you are signing is never uploaded.
- Merge PDFs — Combine several PDFs into one, in your browser. Nothing is uploaded, there is no account, and there is no page limit.
- The full editor — annotate, sign, fill forms, redact, OCR and more.
Part of messy-ui. Free, open source and account-free — see also the countdown timer.