On-device and cloud OCR solve the same problem with different tradeoffs — the gap in raw capability has narrowed significantly in recent years, shifting the real decision toward privacy and reliability rather than accuracy alone.
Accuracy
Cloud OCR services historically had an edge from larger, more frequently updated models, but modern on-device frameworks like Apple's Vision have closed most of that gap for standard printed text in common languages.
Speed and reliability
On-device OCR runs instantly with no network dependency — no waiting on an upload, no failure if you're offline or on a poor connection, which matters in practice far more often than the accuracy difference does.
Privacy
On-device OCR never transmits the document's actual text content anywhere, which is the clearest, least ambiguous advantage — there's no server log, no transmission, nothing to potentially retain.
Is handwriting recognition better with cloud OCR?
Cursive and stylized handwriting remains genuinely harder for both approaches, but the gap between on-device and cloud handwriting recognition has also narrowed considerably as on-device models have improved.