#Next.js

A comprehensive developer's review of Next.js Partial Prerendering (PPR). Learn how it blends the performance of static shell generation with the flexibility of dynamic runtime components using React Suspense.

Everything I hit while converting from Pages Router to App Router — migration strategy, Server Component gotchas, data fetching rewrites, and honest before/after performance numbers.

A practical guide to building streaming AI chat in Next.js with the Vercel AI SDK. Covers useChat, Server Actions, switching providers, tool integration, and handling loading and error states with real code.

Adding English to a Korean-only blog with next-intl. Lessons from implementing i18n in Next.js App Router, including routing, message files, and Server Components.

I built a service and nobody came. How I implemented technical SEO in Next.js to drive organic traffic without a marketing budget.

I was tired of users reporting errors before I knew about them. How I set up Sentry in a Next.js project for real-time error tracking and alerting.

SSR pages showed blank screens for 3 seconds during data loading. Streaming SSR sends ready parts first, dramatically improving perceived speed.

Creating API routes, fetch calls, loading states... Too much code for one form. Server Actions dramatically simplified form handling.

Passing a function as props from a Server Component broke everything. Understanding the serialization boundary revealed RSC's true patterns.

Images were 80% of my page weight. Format conversion to WebP/AVIF and responsive images dramatically improved loading speed.

Your beautiful hero image killed the LCP score? Understand how `next/image` optimizes format (WebP/AVIF), resizing, and layouts. Deep dive into `sizes` prop and `blurDataURL`.

Digging into the CommonJS vs ES Modules conflict that causes "Named export not found". A complete guide from package.json exports to transpilePackages.

Do you know what the Circle (○) and Lambda (λ) symbols mean in Next.js build logs? Ensure you aren't accidentally making every page dynamic.

ISR works perfectly on Vercel, but fails on AWS/Docker. Let's dig into the file system cache trap and how to solve it.

I tried to save money by deploying to AWS S3 instead of Vercel, but ended up with a broken site. I share the three nightmares of Static Export (Image Optimization, API Routes, Dynamic Routing) and how to fix them.

Imagine a user clicking 'Checkout', logging in, and then landing on the Home page instead of the Checkout page. They will leave. I share how detailed redirect logic recovered sales, and how to prevent Open Redirect vulnerabilities during implementation.

Users rage-quit my shopping app because hitting 'Back' reset their scroll position. Here's how I fixed Scroll Restoration in Next.js SPA.

My React code crashed with 'window is not defined' in Next.js. Here's why Server Side Rendering (SSR) breaks browser APIs and 3 robust ways to fix it (useEffect, typeof check, Dynamic Import).

I imported a Server Component inside a Client Component, and it broke everything. Here’s how to use the Composition Pattern (Donut Pattern) to fix it and correctly separate Context Providers.

Stop adding 'use client' to every file. I explain the clear boundary between Server and Client Components, and how to implement interactivity without sacrificing performance in Next.js App Router.

One week after launch, I got an angry email: 'I lost all my work because I was logged out!' The culprit was JWT expiration. I share the hard lessons learned about balancing security and UX, implementing Silent Refresh with Axios Interceptors, and choosing the right storage to prevent XSS attacks.

I found my website running inside an iframe on a shady domain. I dive deep into 6 essential security headers (HSTS, X-Frame-Options, CSP, Permissions-Policy, etc.) to stop Clickjacking and XSS, with implementation guides for Nginx and Next.js.

I updated the database, but the page still shows old data. We analyze the powerful (and evil) caching mechanism of Next.js 13+ in 4 layers, compare it with React Query, and share practical debugging strategies.

My admin account was hijacked because of a single comment on the board. I dive deep into the 3 types of XSS (Stored, Reflected, DOM) and concrete defense strategies in React/Next.js environments, including HTML Escaping, CSP, and Cookie Security.

Stop worrying about naming collisions in CSS. Discover how CSS Modules locally scope your class names by generating unique hashes. This guide covers the fundamentals, common pitfalls, advanced composition features, framework comparisons, and how to seamlessly integrate with TypeScript for type-safe styling.

Fix the 'async/await is not yet supported in Client Components' error in Next.js once and for all. This comprehensive guide explores the architectural differences between Server Components and Client Components, explains why React Hooks conflict with async rendering, and provides three robust strategies for data fetching: passing data from Server Components, using useEffect, and leveraging libraries like TanStack Query.

I share how I almost got hacked by protecting admin pages with `useEffect`. Learn why client-side protection is dangerous and how to use Next.js Middleware to securely protect routes at the server level, including a deep dive into Edge Runtime limitations.

My images were fine until I used Next.js's `<Image>` component, which immediately threw errors. I realized this wasn't just a config issue, but a security measure to protect server resources. I explain how to configure `remotePatterns` and dive deep into how Next.js Image Optimization works under the hood.

My API key worked fine locally but showed `undefined` in the browser console. I share my 3-hour debugging struggle caused by misunderstanding Next.js's 'Server-Client Boundary' and how I almost leaked my secret keys.