PDF OCR - Free PDF OCR Online, OCR Scanner & Converter

PDF OCR - Free PDF OCR Online, OCR Scanner & Converter

What Is PDF OCR?

OCR stands for Optical Character Recognition. A technology that converts different types of documents, such as scanned paper documents, PDF files, or images captured by a digital camera, into editable and searchable data. Online OCR tool analyzes the shapes and patterns of the characters in a document and converts them into machine-readable text. 

What Is the Purpose Of PDF OCR?

OCR technology allows for the extraction, editing, search, and analysis of text from PDFs, making it simpler to manage and work with digital content. The technology finds its application in different areas, such as document management, data entry automation, and accessibility enhancement for those with visual impairments.

How does PDF OCR Work?

Optical Character Recognition (OCR) technology follows a series of steps starting from image processing, pattern recognition, and language modeling. Here is a simplified overview of the typical working process of OCR technology:

Image Acquisition

First, an image of the document containing text is obtained from various sources such as scanners, cameras, or digital files. Preprocessing: The image is then preprocessed to enhance its quality and accuracy of OCR. This may include tasks such as noise reduction, contrast adjustment, and image binarization (converting the image into black and white).

Text Detection

The preprocessed image is analyzed using OCR software to identify regions containing text, including individual characters, words, and paragraphs.

Character Segmentation

Once the text regions are detected, the software segments the characters within these regions to separate them for recognition.

Feature Extraction

For each segmented character, OCR software extracts a set of features that describe its shape, size, and other relevant characteristics to distinguish one character from another.

Character Recognition

Using pattern recognition algorithms, OCR software compares the extracted features of each character against a predefined set of character templates or models. This matching process helps recognize the characters.

Language Modeling

In addition to character recognition, OCR software considers the context of the text by employing language modeling techniques that recognize the likelihood of certain words or phrases occurring together in a given language.


After character recognition, OCR software may perform additional processing to refine the results and correct any errors, such as spell-checking, error correction, and formatting adjustments.


Finally, the OCR software outputs the recognized text in digital format such as plain text, formatted text, or searchable PDF files. The outputted text can then be used for various purposes like editing, searching, or indexing.


OCR technology plays a vital role in digitizing and extracting text from scanned documents, offering benefits such as preservation, accessibility, searchability, text extraction, workflow efficiency, integration with digital systems, and compliance with regulations.

How To Use PDF OCR 

If you have a scanned PDF document that you need to convert into searchable text, BlueSEOTools Online PDF OCR is a great online platform to use.

To get started, you'll want to navigate to the OCR PDF tool.

open pdf ocr tool to apply ocr on pdf

From there, you can upload a scanned PDF and initiate the OCR process by clicking the "Select OCR" button.

selectpdf files to apply ocr

Depending on the size and complexity of the document, the OCR process may take some time to complete, so be patient. Apply OCR on PDF by clicking on the "Apply OCR" button.

apply ocr on pdf by clicking on button

Once the process is finished, you can review the results for accuracy and quality, and then save or export the converted text to your desired output format.

You can repeat this process as necessary for any additional scanned PDFs that you need to convert. With BlueSEOTools, you can quickly and efficiently digitize your document collections with ease.

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