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What is OCR And How Does It Work?

Transforming PDF documents into editable text can be a daunting task for many. Searching and editing text within PDFs often proves time-consuming. Thankfully, Optical Character Recognition (OCR) technology has emerged as a game-changer. OCR integrates seamlessly into many modern PDF editors, significantly enhancing the efficiency of digital file searches and edits. This article delves into the process of converting PDFs to text, explores its advantages, and recommends top OCR-powered applications.

What is OCR?

Optical Character Recognition (OCR) is a technology that converts images or scanned documents into editable and searchable text.

OCR stands as a revolutionary technology within PDF conversion, utilizing artificial intelligence to interpret text captured by cameras or scanners and transforming it into editable text. This advanced system not only eradicates laborious data entry but also mitigates human errors. It adeptly deciphers handwritten text and image files, translates text from smartphone-captured images, and enables efficient keyword searches within documents. Let’s delve into 4 distinct scenarios highlighting the practicality of converting PDFs to text.

Digital Storage

By converting PDFs to text, documents, and brochures obtained from clients can be transformed into searchable text, optimizing data management. This conversion minimizes storage space while expediting information retrieval. With the search function, users can efficiently locate vital data within documents, reducing the time traditionally spent on manual searches. 

OCR simplifies text conversion through scanning, eliminating manual typing when transcribing printed, handwritten, or image-based text. This efficient process drastically reduces data entry time and effort at a minimal cost. Beyond printed text, OCR adeptly translates handwritten notes and text within images into editable digital formats, streamlining data entry tasks across diverse content sources.

Business Card Management

In a bustling business environment, exchanging business cards is a common practice. However, managing and organizing these physical cards can pose significant challenges. Leveraging OCR technologies combined with the capabilities of Document AI offers a transformative solution. By digitizing business cards into searchable text, professionals can transcend the limitations of physical storage. This digital transformation not only optimizes space but also revolutionizes accessibility and organization. Imagine swiftly searching and retrieving specific contacts or categorizing cards by company names effortlessly.

Moreover, the integration of new business cards seamlessly with existing contacts ensures a comprehensive and up-to-date digital Rolodex. This streamlined approach not only enhances efficiency in networking but also ensures that valuable contacts are easily accessible and never misplaced, empowering professionals to navigate their business relationships seamlessly.

Searching, Copying, and Pasting in PDF Files

When it comes to editing PDF files, using OCR features within a PDF editor equipped with built-in Document AI is a useful option for everyone. This integrated technology enables seamless text extraction and manipulation within PDFs. With OCR capabilities alongside Document AI, users can effortlessly convert scanned or image-based content into editable text. This transformation empowers efficient editing, ensuring that previously static documents become dynamic and customizable, enhancing productivity and the versatility of PDF files. Setting the resolution to 200-300 dpi further enhances OCR accuracy, ensuring precise text extraction for improved search results and seamless data retrieval.

Safeguarding Privacy

OCR technologies, coupled with the prowess of Document AI, offer a robust solution for safeguarding sensitive information within documents. By utilizing redaction tools empowered by OCR, users can seamlessly identify and redact confidential data, such as personal details, proprietary content, or legal documents, ensuring enhanced privacy and security. This transformative application of OCR and Document AI empowers individuals and organizations to protect sensitive information effectively, mitigating risks and maintaining confidentiality across digital documents.

How to Convert PDF to Text with OCR

Below are the steps to extract text from PDF using PDF Reader.

  1. Open the PDF file, and click on the “OCR” button from the toolbar (Windows)
Win_OCR PDF_01
  1. Or you can click “Tool” > “OCR” from the top menu bar (Mac)
Mac_OCR PDF_01
  1. Choose how you want to apply OCR to the PDF, including selecting the page(s) you wish to apply OCR on, the language applied, and the location to export the results.
Win_OCR PDF_02
  1. Choose an output folder and click “OK” to start conversion.

In addition, there are two primary methods for converting PDF to text: utilizing online services and dedicated applications.

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Convert PDFs to Text Online

Online OCR services provide convenience and accessibility by enabling users to effortlessly upload PDF files onto web platforms for rapid conversion. These platforms leverage OCR technology seamlessly, efficiently transforming paper documents or images into editable text. The beauty of online OCR lies in the liberation of device limitation, without the necessity for downloading any additional software or applications. However, it’s crucial to consider potential security implications when uploading sensitive documents to external servers. Balancing convenience with security is key when utilizing online OCR services.

Converting PDFs to Text with An App/Software

In contrast, dedicated OCR applications offer a hands-on approach, providing advanced features, customization, and offline functionality. Tailored to specific user needs, these apps ensure precise text extraction, formatting adjustments, and greater control over conversions. Some paid apps offer free trial periods, ideal for temporary or comprehensive use, enabling users to assess functionality before they make the purchase. Also, if the OCR software/app is compatible with a variety of devices, it can be used on PCs, smartphones, iPads, and other tablet devices, allowing you to view and edit PDF files across devices.

Is OCR Safe?

Individuals dealing with confidential documents or frequent document exchanges often prioritize tool security. For enhanced safety, opting for local work is advisable. While many online PDF editing services enforce file deletion policies, minimizing data exposure, uploading files online poses inherent risks of potential information leaks during transfer. For a more secure environment, utilizing installed PDF editing applications within a local environment offers heightened security and control over sensitive documents.

How to Improve the Accuracy of OCR?

Advancements in OCR technology have significantly enhanced reading accuracy. Consider the following five key factors when scanning and converting text for improved OCR accuracy.

Setting the Resolution to 200~300 DPI

Scanners offer resolution options; higher settings enhance character recognition accuracy during scanning.

Opting for Black Text on a White Background

Choose black text on a white background for optimal recognition, as colors other than black or white may result in misinterpretation.

Improving Text Recognition

Text from old documents or handwritten text may not be recognized correctly. Adjust color contrast post-scanning to significantly improve OCR accuracy when reading the text.

Ensuring Text Alignment

Avoid tilted or slanted fonts as they impact reading accuracy. For handwritten content, strive for a straight orientation to enhance OCR precision.

Preventing the Scan of Transparent Papers or Documents

Thin papers like newspapers may lead to text recognition issues due to text bleeding from the reverse side. Placing a dark file beneath prevents text transparency, enhancing accuracy during scanning.


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Best OCR Software Recommendation

Meet KDAN PDF Reader—an all-in-one PDF editing application offering robust features, including OCR functionality accessible through its premium version. With a wide range of scanning, adjustable settings post-scan, and text and image scanning support, it seamlessly integrates scanned data into various documents. Supporting nearly 100 languages, its automatic language detection ensures highly accurate text conversion, while its extensive editing tools allow file manipulation, encryption, and conversion to multiple formats within a single, versatile application.

High Compatibility

KDAN PDF Reader seamlessly operates across various platforms—iPhone, iPad, Androids, Mac, Windows, and more. Its universal compatibility ensures a consistent experience across different operating systems, eliminating concerns about device disparities.

Cloud Storage Service

KDAN PDF Reader offers complimentary cloud storage powered by KDAN Cloud. Seamlessly access, edit, add text/objects, and manage documents stored in the cloud, ensuring convenient document creation and management

Versatile Features

You can perform various PDF editing with only one PDF Reader without installing multiple applications. PDF Reader provides the following functions. 

  • Add text or images
  • Edit text directly
  • Annotate, underline, text
  • Add watermarks
  • Set passwords
  • Add electronic signatures
  • Scan file and OCR functions
  • Rotate, trim, insert, replace, split, merge PDF pages, etc.

Beyond OCR: Exploring Diverse Data Recognition Technologies

There are some other technologies, which are related to OCR but focus on different aspects of data recognition and interpretation. The evolving landscape of Document AI integrates these technologies, harnessing their collective power for comprehensive document understanding and processing, revolutionizing data interpretation across varied formats.

Intelligent Character Recognition (ICR)

Similar to OCR, ICR deals with recognizing characters, but it goes beyond printed or typed text. ICR specializes in handwriting recognition, enabling machines to interpret and convert handwritten text into digital characters.

Magnetic Ink Character Recognition (MICR)

MICR is a specific type of recognition primarily used in banking. It’s specialized for reading characters printed with magnetic ink. MICR technology helps banks process checks by interpreting the magnetic ink characters, typically found at the bottom of checks, for faster and more accurate processing.

Speech Recognition

Unlike OCR, which deals with visual data, speech recognition involves interpreting spoken language and converting it into text or commands. While not directly related to visual text recognition, speech recognition technology shares similarities in terms of interpreting and transcribing information, albeit from an auditory source.

These technologies share the overarching goal of interpreting and transforming various forms of data into usable digital formats, but they specialize in different input sources or formats. Take advantage of their power to achieve your goals!


In the world of productivity tools, OCR emerges as a game-changer. Its ability to swiftly convert PDFs into editable text streamlines workflows and saves precious time. It is essential to understand how OCR can be used to enhance document management, regardless of whether you use online services for convenience or dedicated applications for accuracy.

Integrating OCR tools like KDAN PDF Reader into daily workflows simplifies document handling and storage across platforms. Embracing OCR not only boosts work efficiency but also simplifies everyday tasks.


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(The featrued image is made by Claudio Schwarz on Unsplash.)