A `manifest.json` file is the meta data file for a browser extension. Different browsers have their own standard. ## Chrome Chrome now supports V2 and V3, but V2 extensions will soon disappear from extension store, and they don't accept new V2 extensions. A Chrome extension will also work on other chromium-based browsers such as Edge. On Edge, you can directly install extensions from [Chrome Web Store](https://chrome.google.com/webstore).