Try ordinary text extraction first
If text in the PDF can be selected and copied correctly, use PDF to text for a faster result. A scan may already contain an OCR layer, but that layer can contain errors. This OCR tool recognizes the selected pages again and exports new text; it does not modify or repair the PDF’s existing layer.
Start with one clear page
The default selection is page 1. Choose English or Simplified Chinese plus English and begin at 150 DPI. For small print, 200 DPI may help within the pixel budget. Upright, sharp, evenly lit printed pages work better than handwriting, low-resolution photos or curved book pages. Rotate incorrectly oriented pages before recognizing them.
Keep the batch small enough for your device
A PDF may contain up to 100 pages and 20 MB, but one OCR job accepts at most 10 selected pages and 40 megapixels. Each page is also bounded. A slow device may exceed the two-minute deadline even within those limits. Reduce the selection instead of repeatedly submitting an entire document. Clearing cancels the processing workers.
Review uncertain details
Compare names, dates, decimal points, minus signs and totals with the source image. Columns and tables can arrive in the wrong reading order; a confident-looking word is not proof of accuracy. Blank recognition results are listed by page. Form fields and annotations are not rendered into the recognition images.
Choose the right output expectation
Download UTF-8 TXT with source page numbers. This is not a searchable PDF, a Word layout or a structured Excel table. The engine and language models load from this site; selected documents, temporary page images and results are not stored in a database or OCR cache. Keep the source scan for review.