Server-side Rendering (SSR)

Also referred to as "SSR" or "Dynamic Rendering".

If a page uses Server-side Rendering, the page HTML is generated on each request.

To use Server-side Rendering for a page, you need to export an async function called getServerSideProps. This function will be called by the server on every request.

For example, suppose that your page needs to pre-render frequently updated data (fetched from an external API). You can write getServerSideProps which fetches this data and passes it to Page like below:

exportdefaultfunctionPage({ data }) {// Render data...}// This gets called on every requestexportasyncfunctiongetServerSideProps() {// Fetch data from external APIconstres=awaitfetch(`https://.../data`)constdata=awaitres.json()// Pass data to the page via propsreturn { props: { data } }}

As you can see, getServerSideProps is similar to getStaticProps, but the difference is that getServerSideProps is run on every request instead of on build time.

To learn more about how getServerSideProps works, check out our Data Fetching documentation.