OCR Accuracy Comparison
OCR (Optical Character Recognition) accuracy depends on the engine, input quality, and language. Here is how the main free and paid options compare.
Engine comparison
| Engine | Where | Accuracy | Languages | Cost |
|---|---|---|---|---|
| Tesseract.js (Irreva) | Browser | Good (printed text) | 60+ | Free |
| Google Cloud Vision | API | Excellent | 100+ | Paid (free tier) |
| Amazon Textract | API | Excellent for forms | Limited | Paid (free tier) |
| ABBYY FineReader | Desktop/API | Best for PDFs | 190+ | Paid |
| Adobe Acrobat OCR | Desktop | Very good | 40+ | Subscription |
When Tesseract (Irreva) is good enough
- Clean, high-resolution printed documents (300+ DPI)
- Simple layouts without complex tables or columns
- Standard Western languages (English, French, German, Spanish)
- Any situation where privacy requires no upload
When to use a paid service
- Handwritten text (Tesseract accuracy drops significantly)
- Complex multi-column layouts or tables
- Degraded or low-resolution scans
- High-accuracy requirement (legal, medical, financial documents)
- Bulk processing of thousands of pages
Frequently Asked Questions
What DPI is needed for good OCR results?
300 DPI minimum for printed text. 600 DPI for small fonts. Below 200 DPI, accuracy drops significantly.
Can OCR read handwriting?
Tesseract has limited handwriting support. Google Cloud Vision and Microsoft Azure Computer Vision are far better for handwritten text.