(a9t9) Free OCR Software

This can be gotten as a Windows App from https://www.microsoft.com/en-us/p/a9t9-free-ocr-software/9nblgggz5nsn , but you would likely find that GImageReader has better screen layout/visibility

very hard to understand this site. it's a total mess. I was not able to find any sources to this, and it seems to have limited functionality on the free version (on top of a watermark on every page).

I am smitten by this service. It recognized all of the text and the layout of this text almost without errors and quickly. This is THE OCR TOOL. Tesseract and programs based on it are not even close to this level. And in addition it can be used for free for small files! For big files there's a monthly fee of $60, which is big, but if you need it just once and desperate for quality, you can do what I did - split your file into pieces of small size, feed them to the service one by one, take the results and merge them back (for pdfs use the right merging tool which saves the text layer like pdf-tk). For best results use algorithm labeled 5, pdf with invisible text option and additional checkboxes for tables and stuff. They also have an API which I haven't tried. It implies that you can write a bash script or a normal program which will feed the pieces to the service automatically. I just don't know whether this API can be accessed for free, you need to check this.

Unfortunately, the maximum input file size is limited to 5 MB.