How is this different from PDF to Markdown or PDF to Word?
Those two read the characters a PDF already contains, which is fast and exact. This one is for the documents that contain none — a scan is a picture of text — and it recognises the shapes instead. If your PDF has a text layer this tool will tell you so and send you to them, because reading what is there always beats guessing at it.
How accurate is it?
On a clean, flat, well-lit scan of printed type, high enough to paste and skim. On a phone photograph of a curved page in poor light, low enough that you should read it against the original. The tool reports its confidence for every word and lists the doubtful ones, so the checking has somewhere to start rather than being a guess about a guess.
Do I get a searchable PDF back?
No. You get the text. Producing a PDF with an invisible text layer laid over the original scan is a different and much larger job — it means writing the recognised characters back into the document at the exact position they were found. It is worth building and it is not built, and saying so is better than shipping something that looks like it and is not.
How long does a long document take?
Seconds per page, on one thread, plus the five-and-a-half-megabyte download the first time. A forty-page scan is minutes rather than seconds. Pages are drawn and read one at a time and released before the next, so memory stays flat — which is what makes a long document possible on a phone at all, if not quick.
Which languages does it read?
English only, in this version. Each additional language is about two megabytes on top of what is already the heaviest engine here, so they arrive as a choice you make rather than a cost everybody pays.
Does the scan leave my device?
No. The renderer, the recogniser, the language model and the recognition all live in this tab. This matters more here than almost anywhere on the site: the documents people scan are contracts, medical letters, payslips and identity papers, and every free online OCR service receives all of them.