How to Extract Hyperlinks from a PDF

Introduction

By definition, a hyperlink, or more simply a link, is a reference to information that the user can access by clicking or tapping.

Hyperlinks help in organizing a document and enhancing its content with outside resources.

Adding hyperlinks to a PDF document gives its readers instant access to data that is either located within the same document, in another document, or a website without the need to duplicate such data.

Quickly scanning a PDF document and grabbing the links included within it is a common user query, mainly used to check the status of these links and to see whether they are working, broken, or malformed.

How links are stored in a PDF file

A link is generally represented in a PDF document cross-reference table using a “Link” tag and objects inside its sub-tree. These objects consist of a link object reference, or link annotation, and one or more text objects. The text object or objects within the “Link” tag are used to provide a name for the link.

The following figure shows a link included within the cross-reference table of a sample PDF file: