In most cases, Adobe PDF files contain static data, not intended for other users to edit. PDF forms, however, can have editable text boxes, allowing you to fill out the form without having to ...

Advanced PDF editing with Adobe Acrobat Standard and Pro All the above, plus: Desktop, mobile and web access Advanced text and image editing Collect e-signatures Track responses Compress PDFs ...

With Adobe Acrobat Reader and Adobe’s online PDF editor, you can add comments, fill out forms, insert text, and even sign documents – all for free.

If you're still editing or creating a PDF, you can see, edit, and create alt text using your PDF-creation program. Visit Business Insider's Tech Reference library for more stories.

In other words, Adobe Reader won't let you add text. What you need is a program that's a little more accommodating, PDF-wise. Try Foxit Reader 4.3, which allows you to add text to any PDF.

Removing text from a PDF isn't as easy as drawing a black bar across it. Fortunately, redaction tools let you truly erase sensitive text in Preview, Adobe Acrobat DC Pro, and PDFPen.