Product scope
The core difference is how much product you want around OCR.
Bottom line
If your main requirement is extraction quality and clean output, LeapOCR is the tighter fit. If you want a broader SaaS workflow, Nanonets can make sense.
LeapOCR
A focused extraction layer
LeapOCR is built for teams that want OCR to do one job well: return structured document output that can slot into the rest of the system. That keeps the contract smaller and makes it easier to fit inside custom workflows.
Nanonets
A broader workflow SaaS
Nanonets is attractive when the buyer wants a wider automation story around document handling. That can be useful, but it also means the team may end up adopting more application surface than it actually needs just to get the extraction step done.