Why IronOCR and not Tesseract


  • Tesseract unable to handle an image that is rotated, skewed, low DPI, scanned, or has background noise
  • Requires image pre-processing using Photoshop or ImageMagick
  • Long processing time before providing nonsensical information
  • IronOCR pre-processing and image filters take this headache away
  • Users often achieve 99.8-100% accuracy with minimal configuration

Image Compatibility

  • Only accepts Leptonica PIX image format which is an IntPtr C++ object in C#
  • PIX objects are not managed memory — failure to handle them with care in C# results in memory leaks
  • Images memory managed
  • PDF & Broad image support:
    • MultiFrame TIFF
    • JPEG & JPEG2000
    • GIF
    • PNG
  • System.Drawing Bitmaps, Stream, and Byte Array/Binary image Data (byte[]) are included for every file format


  • Poorly documented settings must be fine-tuned to provide accurate
  • Dependent on clean documents/pre-processed images
  • Zero configuration works accurately and at speed for most images
  • Multithreading makes full use of multi-core processors
  • Even low-resolution images generally work with a high degree of accuracy
  • No Photoshop required



Little to no support, not beginner friendly:

  1. Work with Interop layers — many found on GitHub are out of date with unresolved tickets, memory leaks, and console warnings
     — May not support .NET Core or Standard
  2. Work with the command line EXE — difficult to deploy and constantly interrupted by virus scanners and security policies
  • A managed and tested .NET Library for Tesseract called IronTesseract
  • Fully documented with IntelliSense support
  • Team of support engineers ready to assist


  • Only 100 languages
  • Over 127 built-in languages + custom language pack support


Tesseract is an excellent resource for C++ developers, but it is not a complete OCR library for .NET. Scanned or photographed images must be pre-processed so as to be orthogonal, standardized, high-resolution, and free of digital noise before Tesseract can accurately work with them.

In contrast, IronOCR can do this and more, with just a single line of code. IronOCR uses a very finely-tuned Tesseract for its internal OCR engine, built for C#, with a lot of performance improvements and features added as standard.