PDF guides

Practical answers to everyday PDF problems: shrinking files, signing, filling in forms and keeping documents private.

How to make a PDF small enough to emailMost email services won’t send attachments over about 20–25 MB. Here’s how to get a PDF under the limit without wrecking it.
Are online PDF tools safe to use?Most online PDF tools upload your file to a company’s server. Here’s what that means, and how to choose a tool you can trust with private documents.
How to sign a PDF without printing itPrint, sign, scan, email: there’s a faster way. Here’s how to sign a PDF on your computer or phone, and when an electronic signature is enough.
How to fill in a PDF form on your computer or phoneSome PDF forms let you type straight into them; others are just pictures of paper. Here’s how to fill in both kinds.
How to password-protect a PDFA password stops anyone without it from opening your PDF. Here’s how to add one properly, and how to share the password without undoing the point.
How to combine PDFs into one file, in the right orderJob applications, visa packs and expense claims often ask for “one PDF”. Here’s how to combine files and get the order right first time.
How to turn phone photos of documents into a PDFNo scanner? Your phone camera is enough. Here’s how to photograph documents so they’re readable, and turn them into a single PDF.
How to extract pages from a PDFNeed page 4 of a 60-page statement, or each chapter as its own file? Here’s how to pull pages out of a PDF.
How to redact a PDF properly (and why black boxes fail)A black rectangle over text often hides nothing: the words are still in the file. Here’s how to redact a PDF so the information is really gone.