If you're wanting to convert an image into text, Google Docs has a powerful Optical Character Recognition feature built right in. Here's how to make it work.

To see alt text in a completed PDF document, you'll need to use a screen reading app, which is an accessibility tool for visually impaired users.

PDF Replacer is a free software to find and replace text in bulk in PDF files. You can choose font types, remove text from PDF files using blank,etc.

Microsoft Edge provides a feature to highlight text in PDF and save highlighted PDF to your PC. This post shows you how to to highlight and save PDF using Edge.