# nextjs-pageweight-analyser This is a simple script I wrote for analysing page weight of a site built using [Next.js], which I what I use [at work]. When we use Next.js, we send data to the page using [getServerSideProps]. These props get rendered as JSON and stuffed inside a ` ``` Sending unnecessary data in these props can bloat the size of the page. This script: * fetches the page * reports the size of the HTML and the `__NEXT_DATA__` specifically * saves the `__NEXT_DATA__` to a pretty-printed JSON file for easy analysis I use this script to analyse the props, to identity ways we can reduce the size of the Next.js data, and to measure the impact of changes. [Next.js]: https://nextjs.org [at work]: https://github.com/wellcomecollection/wellcomecollection.org [getServerSideProps]: https://nextjs.org/docs/basic-features/data-fetching/get-server-side-props ## Usage You need Node installed. Download the `measure.js` from this repo. The script takes two arguments: * the URL to fetch (required) * a label for the downloaded files (optional) Example: ```console $ node measure.js https://wellcomecollection.org/collections collections HTML = 196.45 kB NEXT_DATA = 52.17 kB (26.6%) Saved HTML to out/collections.html Saved JSON to out/collections.json ```