diff-viewer is a browser tool developed by mizutoki79 that allows users to view diffs directly in their browser. The program consists of an editor on the top half of the screen and a results display on the bottom half. The editor is divided into two sections, with the left side showing the original content and the right side showing the modified content for comparison.

One of the key features of diff-viewer is its real-time updating. Any changes made in the editor are immediately reflected in the results. This allows users to see the differences between the original and modified content in real-time. Additionally, diff-viewer supports syntax highlighting for JSON, making it easier to read and understand JSON files.

Users can also format the input content if it is in JSON format by pressing Alt + Shift + F. This feature helps improve the readability of JSON files, making it easier to analyze and compare different versions.

Overall, diff-viewer is a useful tool for anyone who needs to view and compare diffs directly in their browser. Its intuitive interface and real-time updating feature make it a convenient choice for developers and users working with JSON files.