renderToStaticMarkup

Similar to renderToString, except this doesn’t create extra DOM attributes that React uses internally, such as data-reactroot. This is useful if you want to use React as a simple static page generator, as stripping away the extra attributes can save some bytes.

renderToStaticMarkup(element)

If you plan to use React on the client to make the markup interactive, do not use this method. Instead, use renderToString on the server and ReactDOM.hydrateRoot() on the client.