Password-protect a PDF without uploading it
Add AES-256 password protection — without the file going anywhere.
Processed on your device — nothing is uploaded. Works offline.
How to password-protect a PDF without uploading it
- 1Choose the PDF.
- 2Type a password and confirm it.
- 3Click Protect. The file is encrypted with AES-256 and you download the protected copy.
Every step runs in this tab. The site has no upload endpoint, and the page's security policy forbids the browser from contacting any other server — see how that is enforced.
When you'd use it
Payslips, tax documents, medical results
Anything you email that you wouldn't want read if the mailbox is breached.
Board papers and drafts
Protected with a password shared over a different channel.
Files on shared drives
A second lock for documents that sit where many people can browse.
Good to know
- Encryption is AES-256, the strongest the PDF standard supports, applied by qpdf compiled to WebAssembly.
- There is no reset. We never see the password, so if you lose it the file stays locked — keep it in a password manager.
Don't trust us — test us
“Your files never leave your device” is a claim every PDF site makes. Here it is checkable in under a minute, three different ways:
- Watch the network.Open your browser's developer tools, switch to the Network tab, then run the tool. The only requests you will see are the site's own files — none of them carries your document — and once the app is cached there are no requests at all.
- Pull the plug. Load this page, turn off your wifi or switch on airplane mode, then use the tool. It keeps working, because there is no server involved and nowhere to upload to.
- Read the headers. The response headers for this page include a Content-Security-Policy with
connect-src 'self': the browser itself refuses to send anything to another host, whatever the code asks.
The full privacy model, including what we can't protect you from →
Guide
How to edit a PDF without uploading it
Most 'edit a PDF' jobs are one of seven things, and all seven can be done in your browser without the file leaving your machine. Which tool for which job, and the honest answer on editing the text itself.
Frequently asked questions
What encryption is used?
AES-256, the strongest encryption the PDF standard supports, applied by qpdf — the same open-source engine used in professional PDF pipelines — compiled to WebAssembly and running in your browser.
What happens if I forget the password?
The file is genuinely encrypted, and we never see or store anything — there is no reset. Keep the password somewhere safe, like a password manager.
Does it work offline?
Yes. After your first visit the whole app is cached by a service worker, so the page loads and every tool works with no connection at all. Load the page, switch on airplane mode, and carry on.
Is there a file size limit?
No hard limit — your device's memory is the ceiling. Files up to a few hundred MB work well on a typical laptop. Very large files may be slow or fail on low-memory devices; nothing is ever truncated silently.
Do I need to create an account?
No. No account, no email, no cookies. The free tools are simply free.
Which browsers work?
Current Chrome, Edge, Firefox and Safari, on desktop and on phones. Phones have less memory, so very large files are better handled on a laptop.