The essentials
If you can select and copy a word in a PDF viewer, there is usually digital text available to extract. If the page is one large image, a conventional text extractor may return little or nothing.
Practical steps
Optical character recognition (OCR) interprets letters from pixels. It is a separate operation and may need human correction, particularly with poor scans or complex Arabic typefaces. This release of SatrPDF does not claim to run OCR.
What to double-check
Compare exported text with the original before relying on it. Columns, tables and right-to-left ordering may lose their layout when written to a plain TXT file.
Explore PDF tools