Next.js is an open-source web development framework created by the private company Vercel providing React-based web applications with server-side rendering and static website generation.

React documentation mentions Next.js among "Recommended Toolchains" advising it to developers when "building a server-rendered website with Node.js". Where traditional React apps can only render their content in the client-side browser, Next.js extends this functionality to include applications rendered on the server-side.