Optical Character Recognition (OCR) is a technique, used to convert scanned image into editable text format. Many different types of Optical Character Recognition (OCR) tools are commercially available today; it is a useful and popular method for different types of applications. OCR can predict the accurate result depends on text pre-processing and segmentation algorithms. Image quality is one of the most important factors that improve quality of recognition in performing OCR tools. Images can be processed independently (.png, .jpg, and .gif files) or in multi-page PDF documents (.pdf). The primary objective of this work is to provide the overview of various Optical Character Recognition (OCR) tools and analyses of their performance by applying the two factors of OCR tool performance i.e. accuracy and error rate.