PDF guides
How to sign a PDF, get one under an email limit, open a locked file you have the password for, and choose between PDF and PDF/A — with the free in-browser tool for each job.
How to make a PDF smallerWhy PDFs get big and how to shrink one for email or an upload form: Mac Preview, Word, Acrobat, Ghostscript, dropping pages, splitting, and better scans.How to remove a password from a PDFRemove the open password or the print and copy restrictions from a PDF you are entitled to: in Chrome, Mac Preview, Acrobat, or free in your browser.How to sign a PDF, free, on any deviceSign a PDF electronically for free on Windows, Mac, iPhone or Android, and learn when an electronic signature is enough and when you need a digital one.What is a PDF? The format, explainedWhat a PDF file is, what is inside one, why it looks the same everywhere, how to open and edit it, and how PDF/A differs from a normal PDF.
Looking for the tools themselves? They are all on the PDF Tools page — free, and nothing is uploaded.