"Even though online surveys are now common, there are still many situations where paper-based surveys are needed. Mark2 is a web application that performs mark recognition. It reads mark information from scanned images of mark sheets and converts it into data. The processed results can be downloaded in Excel format. Anyone can use Mark2 free of charge. Mark2 is developed with Blazor WebAssembly, which allows for efficient image processing without uploading image files. This system has been used in answer sheets for academic achievement tests, surveys of residents by local governments, and surveys of visitors to sporting events."