Pro Next js Tip: Detect Device, Browser & OS on Server Side Render using User Agent скачать в хорошем качестве

Pro Next js Tip: Detect Device, Browser & OS on Server Side Render using User Agent

Want to know if your users are on mobile or desktop — before your page even hits the browser? In this video, you’ll learn how to detect the user’s device type, browser, and operating system in Next.js using the User-Agent string, all from the server side — with zero delay or hydration flicker. We’ll start by breaking down what the User-Agent is, how it’s formed, and why it’s sent with every HTTP request. You’ll learn how to extract it from both getServerSideProps and custom route handlers — including /app/api or /pages/api endpoints — and how to parse it cleanly for real-world use. Why does this matter? Because Tailwind handles styling, but sometimes your JavaScript logic — like click events or form submissions — needs to know exactly what kind of device the user is on. And in server-rendered apps like Next.js, relying on window.navigator alone leads to problems like undefined states or flickering layouts after hydration. We’ll cover: ✅ What the User-Agent string is and how it’s structured ✅ How to detect mobile vs desktop using regex or parsers ✅ Using it inside getServerSideProps for first-render props ✅ Parsing User-Agent info in route handlers (API routes) ✅ Using device type in JavaScript logic, not just styling ✅ Avoiding common SSR pitfalls in Next.js apps 🎯 Whether you’re building responsive layouts, tailoring logic to mobile users, or optimizing performance — this is a must-know technique for serious Next.js developers. 🔗 Resources 📦 UAParser: ua-parser-js for advanced UA parsing 🔔 Subscribe for More For more SSR techniques, performance best practices, and real-world Next.js tips — hit subscribe and turn on notifications. Let’s build smarter web apps. 🚀 Chapters: 00:00 Intro 01:53 What is User-Agent 03:09 Initial state problem definition 05:20 How to pass and parse User-Agent to client? 15:12 Testing the solution 15:35 How to retrieve & parse User-Agent in route handler? 16:16 Outro