OCR accuracy is influenced more by the quality and structure of the source than by any single recognition setting.
Start with focus, contrast and straight pages
Small characters need enough pixels to be distinguishable. Motion blur can turn 8 into 3 or merge punctuation into nearby letters. Use a stable camera or scan, fill the frame with the page and avoid strong perspective distortion.
Even lighting helps the recognizer separate text from background. A shadow crossing a table can look like a border, while glare can erase light print.
Choose the language that matches the document
OCR engines use language models to decide which character sequences are plausible. Selecting the correct language is especially important when scripts differ or when the document contains mixed English and Hindi text.
Do not assume language selection will correct a poor image. It improves recognition choices, but the engine still needs visible character shapes.
Use DPI as a processing choice, not a magic fix
Rendering or processing at 300 DPI is often sufficient for normal printed documents. Higher settings can help small or faint text by giving recognition stages more pixels to work with, but they also use more memory and time.
If the source itself is only a small screenshot, processing it at 400 DPI does not create genuine missing detail. A better original is preferable to extreme upscaling.
Verify the characters that matter most
Names, dates, totals, decimals, minus signs, account numbers and table columns deserve deliberate review. OCR can produce fluent-looking text while still changing one critical character.
Keep the source image or PDF next to the editable output. For business, academic, legal, medical or financial material, treat OCR as an extraction aid rather than an independent source of truth.
- Check focus before uploading.
- Correct skew and perspective.
- Use the matching OCR language.
- Review numbers and table structure against the source.
Frequently asked questions
Does 400 DPI guarantee better OCR than 300 DPI?
No. Higher processing resolution may help small text, but it cannot restore detail that the source never captured.
Which OCR errors are most dangerous?
Errors in totals, decimals, minus signs, dates, names and identifiers can change the meaning of a document and should be checked carefully.
Why do tables need extra verification?
OCR must recognize both text and the row/column structure, so a correct value can still be placed in the wrong cell.
About this guide
Online AI Apps publishes practical workflow guidance for its own tools and related file-handling tasks. We describe limitations instead of promising perfect conversion, OCR or compliance. For official, legal, medical, financial, tax or identity-document requirements, verify the result with the relevant authority or professional source.