Lock and unlock. Protect PDF encrypts a file with AES-256 and a password you choose, with optional limits on printing, copying and editing. Unlock PDF saves a copy without the password when you know it; it cannot guess or recover a forgotten one. Send the password by a different route from the file, such as a message instead of the same email.
Hide what should not be seen. Redact PDF burns black boxes into the page and turns those pages into images, so the covered text cannot be copied or recovered. Its search finds only text the PDF actually stores, so scanned pages need boxes drawn by hand. Covering text with a coloured rectangle in an ordinary editor does not remove it, which is why the redaction guide explains how to do it properly.
Clean the details around a file. Photos often carry GPS location, camera model and time; Clean photo metadata shows what is inside and re-saves the picture without it. PDFs can carry an author, software and dates; Clean PDF metadata strips them into a copy. Blur faces in photos hides faces or number plates before you share a picture.
For a sensitive document, a sensible order is to redact what must not be seen, clean the metadata, then protect the final file with a password and share the password separately. Know what each step does not do. Cleaning metadata does not hide visible text, redaction turns pages into images so bookmarks and form fields are lost, and a password protects the file but not from someone who has it. Keep the original for your records.
Not sure a PDF site is safe? Read how on-device PDF tools work, how to check whether a site uploads your files, and the comparisons with other PDF sites, which quote competitor figures as of October 2026. The guides are written in plain English and explain the limits as well as the steps. Everything here is free and needs no account.