Guides
- How to compress a PDF for emailWhy PDFs get too big to email, what compression actually changes, how to choose a level, and what to do when compressing doesn't make the file smaller.
- How to check if a PDF website uploads your filesA step-by-step method to see whether an online PDF tool sends your files to a server, using your browser's developer tools, offline mode and the CSP.
- How to sign a PDF without printing itSign a PDF by drawing, typing or uploading your signature, and learn the difference between an electronic signature and a certificate-based digital signature.
- How to merge PDF files without uploading themCombine several PDFs into one file privately, in your browser or with built-in Mac tools, plus tips on page order, file size and locked files.
- How to redact a PDF properly (and why black boxes often fail)Black boxes and highlighting don't remove text from a PDF. Learn how real redaction works, how to do it on your device, and what to check before sharing.
- How to turn a scanned PDF into searchable textWhat OCR is, how to prepare scans for accurate text recognition, and how to make a scanned PDF searchable on your own device without uploading it.