This post helps to add a text box to PDF using a free software and an online tool. You can adjust the size of text box, text style, etc.

Did you know you can add a text box filled with color or a unique shape to your Google Doc? Here's where you'll find that feature in Google Drive.

Google is adding a useful new PDF editor capability to its Chrome browser in the name of accessibility. Optical Character Recognition (OCR) technology lets users convert PDF files to text.

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.