6 Top Open-Source OCR Tools: An Honest Review

When open source OCR tools appeared they were a game-changer for data analysis. But before you start using one, you should know their pros and cons.

June 28, 2023
6 minutes
Find the best open source OCR tools and their AI alternative
Find the best open source OCR tools and their AI alternative

Table of Contents

In the rapidly evolving world of data digitisation, Optical Character Recognition (OCR) tools play a pivotal role in transforming unstructured content into analysable structured data.  

While proprietary OCR solutions have long dominated the market, the emergence of open-source OCR tools promises to be a viable competitor.  

But are they all they’re cracked up to be?  

Let’s delve into an honest review of six popular open-source OCR tools, exploring their strengths and limitations to help you make an informed decision for your OCR requirements.

Why Choose an Open Source OCR?

Open-source OCR tools are a decent option for businesses that have expert dev teams ready to put in the work and the hours into integrating them with other tools. Even then, they might not be the best option for a business that needs to do high-accuracy processing, such as extracting data from invoices.  

Here’s why they are great and also why they need to be taken with a grain of salt:  


  • Cost-effectiveness: Unlike proprietary OCR software which often requires hefty licensing fees or subscription costs, open-source OCR tools are typically free to use. This affordability allows businesses with limited budgets, but strong IT teams to use powerful OCR technology without breaking the bank.

  • Transparency and Customisability: The source code of open-source OCR tools is openly available, allowing users to understand and verify how the OCR engine functions. Additionally, the open nature of the code enables customisation and adaptation to specific requirements, making open-source OCR tools highly versatile for those that have the necessary knowledge and the time to make this happen.

  • Continuous Development and Support: Open source projects often benefit from a vibrant community of contributors who actively participate in the development and maintenance of the software. This means that some open-source OCR tools tend to receive regular updates, bug fixes, and performance enhancements. Furthermore, the community-driven support forums and documentation associated with open-source projects provide valuable resources for troubleshooting and assistance. On the other hand, the reliability of such updates is not consistent or uniform.

  • Language and Platform Diversity: Open-source OCR tools have gained popularity because they tend to offer extensive language support, including both widely spoken and less common languages. Additionally, these tools are often platform-agnostic, allowing you to use them on different operating systems such as Windows, macOS, and Linux.

6 Popular Open-Source OCR Tools

While there are plenty of open-source OCR tools around, the following six have been tried and tested, and perform well within their capabilities.

1. Tesseract

Tesseract is a highly regarded open-source OCR engine initially developed by Hewlett-Packard and now maintained by Google. Known for its accuracy and versatility, Tesseract can extract data and convert scanned documents, images, and handwritten prose into machine-readable text. With support for over 100 languages and compatibility with multiple operating systems, Tesseract offers a convenient command-line interface for OCR tasks.

Pros of Tesseract:

  • Accuracy: Tesseract delivers impressive OCR accuracy, particularly for machine-printed text and well-scanned documents, making it suitable for various applications.
  • Language Support: Tesseract's extensive language support allows for the recognition of text in numerous languages, including less common ones, making it ideal for multilingual applications.
  • Continuous Improvement: Tesseract benefits from an active community of developers, ensuring regular updates, bug fixes, and performance enhancements based on user feedback.

Cons of Tesseract:

  • Complex Layouts: Tesseract performs best on documents with straightforward layouts but may struggle with complex layouts, requiring additional pre- or post-processing steps.
  • Handwriting Recognition: While Tesseract excels at recognising machine-printed text, its performance on handwritten text varies and may not be as accurate as dedicated handwriting recognition tools.

2. OCRopus

OCRopus, developed by Google, is a collection of OCR-related tools that expands upon the capabilities of the Tesseract OCR engine. It offers advanced functionalities for layout analysis, text recognition, and training data generation.  

Pros of OCRopus

  • Layout Analysis: OCRopus excels in precise layout analysis, making it ideal for documents with complex layouts or multi-column structures.
  • Advanced Text Recognition: By leveraging Tesseract's accurate OCR engine and additional components, OCRopus improves recognition accuracy, especially for challenging documents.
  • Customisability: OCRopus empowers you to generate training data and create custom OCR models tailored to specific requirements, allowing for greater control and improved accuracy in specialised applications.

Cons of OCRopus

  • Learning Curve: OCRopus has a steeper learning curve compared to standalone OCR engines due to its range of tools and components.
  • Resource Intensive: The advanced functionalities of OCRopus may require more computational resources, and you should consider hardware requirements and processing time for large-scale or time-sensitive projects.


GOCR is an open-source OCR engine developed under the GNU General Public License. It’s designed to recognise text from various image file formats and supports several languages and operating platforms.  

While it may not offer the same level of accuracy as some other OCR engines, GOCR's straightforward approach makes it accessible to users who prioritise simplicity and require basic OCR functionality.

Pros of GOCR

  • Simplicity: GOCR's primary strength lies in its simplicity. The software offers a straightforward and easy-to-use interface, making it suitable for users who prefer a simple OCR solution without the need for extensive configurations or complex setups.
  • Language Support: GOCR supports multiple languages, allowing users to extract text from images containing diverse linguistic content.  

Cons of GOCR

  • Accuracy: While GOCR is functional and provides basic OCR capabilities, its accuracy may not match that of more advanced OCR engines. But be aware that the recognition results may vary, especially for complex or low-quality images.

  • Advanced Features: GOCR focuses on simple OCR tasks and may lack advanced features like layout analysis or specialised recognition algorithms. So if you require advanced functionality, another tool will be better.

4. CuneiForm

CuneiForm is an open-source OCR that specialises in converting scanned documents and images into editable text.  It’s primary objective is to provide you with accurate OCR results while offering flexibility in terms of input sources and output formats.

CuneiForm also supports multiple languages and is compatible with various operating systems.

Pros of CuneiForm

  • Accuracy: CuneiForm is known for its accuracy in recognising text from scanned images, producing reliable OCR results even for complex documents.
  • Language Support: CuneiForm supports a wide range of languages, enabling users to extract text from documents in different linguistic contexts.
  • Input and Output Flexibility: CuneiForm accepts scanned images in various formats, including TIFF and JPEG, allowing you to work with diverse input sources. Additionally, you can output the recognised text in formats like TXT, HTML, and PDF, offering flexibility for further processing and use.

Cons of CuneiForm

  • User Interface: CuneiForm's user interface may not be as intuitive or user-friendly as some other OCR tools. So you may require some familiarity with OCR software or documentation to effectively navigate and use its features.
  • Customisation: While CuneiForm provides accurate results for general OCR tasks, it may have limitations when it comes to customisation or specialised OCR requirements.

5. Ocrad

Known for its simplicity and speed, Ocrad offers a lightweight solution for basic OCR tasks and is primarily known for recognising printed text. It aims to provide a simple and efficient OCR solution, prioritising speed and ease of use for basic text extraction needs.

Pros of Ocrad

  • Simplicity and Speed: Ocrad's straightforward design and lightweight nature contribute to its simplicity and fast performance. It’s a suitable choice if you’re looking for a quick and uncomplicated OCR solution.
  • Printed Text Recognition: Ocrad excels in recognising printed text from scanned images, delivering reliable results for documents with clear and well-formed printed characters.

Cons of Ocrad

  • Advanced Features: Ocrad's primary focus is on basic OCR tasks, and it may lack advanced features such as layout analysis or support for handwriting recognition.  
  • Accuracy with Complex Text and Poor Quality Images: Ocrad's accuracy may decrease when dealing with complex text structures or low-quality scanned images. You should be cautious when using Ocrad for challenging documents or situations that require high accuracy.

6. GImageReader

With its user-friendly interface and support for multiple languages, GImage Reader aims to provide a convenient solution for basic OCR tasks.

The tool can recognise text from various image file formats, making it suitable for extracting text from scanned documents, screenshots, or photographs. It offers a simple and intuitive user interface, allowing you to quickly load images and obtain text results.

Pros of GImage Reader

  • User-Friendly Interface: GImage Reader prioritises ease of use with its intuitive interface, making it accessible to users without extensive technical knowledge, enabling you to easily load images and receive results.  
  • Language Support: GImage Reader supports multiple languages, allowing you to extract text from images containing different linguistic content.

Cons of GImage Reader

  • Advanced Features: GImage Reader primarily focuses on basic OCR tasks like other open-source options on this list, meaning they’re not suitable if you need specialised recognition.
  • Accuracy and Performance: While GImage Reader is functional for basic OCR tasks, its accuracy and performance may vary depending on the quality of the images and the complexity of the text.  

Why Aren’t More People Using Open Source OCRs?

The rise of open-source OCR tools has ushered in a new era of accessibility and affordability in the world of optical character recognition.

Despite their many advantages, why aren't more people flocking to these open-source solutions? The answer lies in the rapid advancements in technology.  

OCR has seen significant progress in recent years, thanks to the advent of artificial intelligence and machine learning. Commercial OCR solutions constantly evolve to leverage the latest cutting-edge techniques, ensuring better accuracy, faster processing speeds, and improved performance.  

In this fast-paced landscape, you can consider an open-source OCR tool from three years ago outdated.

Furthermore, open-source OCR tools, while powerful and cost-effective, lack the competitive advantage that proprietary solutions can offer.  

Companies often seek an edge over their competitors by leveraging state-of-the-art OCR technology. Plus, they’re supported by dedicated teams of developers who provide ongoing updates, dedicated customer support, and integration with other advanced business tools.

This is where our Affinda shines, powered by VEGA, our AI engine.

With Affinda, you gain access to a comprehensive and highly accurate AI engine that harnesses the latest advancements in artificial intelligence.

Try its unparalleled speed and exceptional accuracy for yourself with a free trial today.

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