OCR.space vs Tesseract OCR

OCR.space converts images and PDF documents into editable text through an online OCR service and API, and can create searchable PDFs. The web service accepts JPG, PNG, GIF, and PDF files without registration; its free web uploads are limited to 5 MB per document. The API returns extracted text in JSON and supports images and multi-page PDFs. It offers three OCR engines: Engine 2 is the default, while Engine 3 supports handwriting, tables, and more than 200 languages. An `isTable` option is recommended for receipts, invoices, and other table-structured documents. The free plan is free, with 25,000 monthly requests and a searchable-PDF watermark; Engine 3 has an additional 2,500 conversions, but cannot produce searchable PDFs. PRO costs $30 a month, PRO PDF costs $60 a month, and Enterprise starts at $999 a month. OCR.space Local runs offline in self-hosted environments; its license price is available from sales.

Tesseract OCR is a free, open-source engine that extracts printed text from images. It can be run from the command line or used through an API; the project does not include a graphical application. It recognizes more than 100 languages out of the box and supports Unicode UTF-8. Version 4 introduced an LSTM neural-network engine for line recognition while retaining the legacy character-pattern engine. Input formats include PNG, JPEG, TIFF, JPEG 2000, GIF, WebP, BMP, and PNM. Output formats include plain text, hOCR, PDF, TSV, ALTO, and PAGE. Tesseract cannot read PDF files directly, although PDF is available as an output format; the documentation suggests converting files or using OCRmyPDF. The project documents wrappers for several languages, including Python, Java, Swift, Flutter, Ruby, Rust, and Go, as well as C and C++ APIs. The repository code uses Apache License 2.0, though dependencies may have different licenses. Image quality may need improvement for better recognition results.