Add a password to a PDF in your browser with pdf-lib. Free, no upload.
No. Core processing stays in your browser. Nothing is uploaded for the main conversion path.
Yes—free without an account. Ads may appear outside the workspace.
Yes. Practical browser limits keep tabs responsive. Split oversized inputs if you hit a warning.
Clear the page when finished and avoid shared kiosks for confidential documents.
After libraries load, core processing can continue locally. First use may download engines.
Add a password to a PDF in your browser with pdf-lib. Free, no upload. Unlike upload converters, this page does not send files to a conversion API.
Use Sibling Tabs above the workspace to open related tools.
Password protection stops casual opening and some exports, but determined attackers may still attempt cracking. Use unique strong passwords, share them out of band, and apply stricter DRM/enterprise controls when the document is highly sensitive.
When the UI exposes permission flags, you can restrict printing or editing. Recipients with advanced tools may bypass soft restrictions—treat permissions as a deterrent, not absolute security.
Keep an unprotected master offline. Recovery without the password is intentionally hard. Unlock PDF only helps when you still know the credential.
Download the result, open it in a second app to confirm it looks right, keep the original source until you no longer need a redo, and clear the workspace on shared computers. If the next step is sharing, rename the file with a date and purpose so teammates know which revision they received. For regulated content, log who received the export.
Very large inputs can exhaust tab memory. Close unused tabs, process a smaller sample first, then scale up. If the tab freezes, split the job into parts and retry. Desktop browsers are more reliable than phones for heavy media work. After success, avoid leaving confidential outputs sitting in the Downloads folder.