Reactjs uses a concept called polyfills to ensure its compatibility across different browsers. A polyfill is a piece of code that provides the technology that you, as a developer, expect the browser to provide natively.
React also includes many built-in safeguards to work well across different environments, taking advantage of JavaScript’s dynamic nature to ensure good performance across a wide range of situations.
React does not attempt to provide a complete “write-once, run-anywhere” solution. Instead, it provides powerful primitives that you can combine to build high-quality user interfaces in both newer and older browsers.
Furthermore, React abstracts many of the complexities of DOM manipulation, providing a simpler programming model and better performance. This allows React to keep the UI in sync with the state of the application seamlessly across different browsers.
While React has good support for many older browsers, some features do require polyfills in older browsers, and there may be compatibility issues with certain older versions of browsers. Always check the specific compatibility table for the version of React you are using.
