Download PDFpen or PDFpenPro if you don’t already have it (free trial available).How to apply OCR to scanned PDFs on Mac PDFpen Let’s take a look at two trusted software options below. While the Preview app on macOS can handle basic editing of PDFs and other documents, it doesn’t have OCR software built-in. If you have a PDF that isn’t searchable it was likely sourced from an image, like a scan. Read on for some options to apply OCR to PDFs on Mac. Do you have a PDF document, but the text isn’t searchable? You can change that with optical character recognition (OCR) software.