NEXT.JS AGENCY FOR SEO-STRONG WEB APPS
We plan, build and run websites and web applications with Next.js – from a new product to migrating an existing React app. We are based in Mönchengladbach and support projects on site in North Rhine-Westphalia and remotely across Germany.
What does a Next.js agency do?
A Next.js agency plans, builds and runs websites and web applications with the React framework Next.js: page structure and rendering strategy, connections to CMS, shop and APIs, performance and technical SEO. nextlevels does this for company websites, customer portals and shop frontends, moves existing React applications to the App Router and runs its own website on Next.js.
What Next.js is – in short
Next.js is an open-source framework based on React for websites and full-stack web applications. It is maintained by Vercel and MIT-licensed, so there are no licence fees. React provides the components; Next.js adds routing, data loading, server rendering and the build.
The current version is Next.js 16, released in October 2025; version 16.3 followed in August 2026. The App Router is the newer of the two routers and supports React Server Components: parts of the interface render on the server and reach the browser as finished HTML. Since version 16, Turbopack is the default bundler, and with Cache Components the team decides explicitly what is cached. The older Pages Router is still supported.
Next.js runs on Vercel, but it can also be self-hosted as a Node.js server or Docker container. For data-heavy interfaces we combine it with TanStack Query and Table. We work out which combination fits your project in the first call.
When Next.js fits – and when it does not
Next.js is not the best choice for every project. This is how we weigh it up:
| Question | Rather Next.js | Rather something else |
|---|---|---|
| Visibility | When content should be found in Google and in AI search: pages arrive as finished HTML from the server. | A React single-page app, when everything sits behind a login and search engines do not matter. |
| Type of project | Company websites, shop frontends and portals with a public and a protected area. | TanStack Start, when you build an app with a lot of interaction and want filters and state typed in the URL. |
| Content | When editors maintain content in a headless CMS and the frontend should be designed freely. | A classic CMS, when editors assemble pages themselves and no development team looks after the frontend. |
| Hosting | On Vercel without further configuration, or self-hosted as a Node.js server or Docker container. | Plain web space without Node.js: Next.js only runs there as a static export with a limited feature set. |
| Team | When your team knows React or you want a large pool of developers and examples. | Angular, when your team is at home there and a large business application with many forms is planned. |
Our assessment from project work, as of October 2026 – not a binding verdict. We work out what fits your project in the first call.
Our Next.js services
New websites & web apps
Company websites, customer portals and SaaS interfaces on Next.js 16 with App Router and TypeScript. Architecture, design system and data layer from one team.
Migration & modernisation
From Create React App, Gatsby or the Pages Router to the App Router. We move route by route, and the application stays shippable throughout.
Headless commerce & CMS
Next.js as the frontend for Shopware or a headless CMS such as our own next-cms – with a preview for editors and pages that update themselves after a change.
Performance & SEO audits
Rendering strategy, bundle size, Core Web Vitals and structured data. You get a prioritised list with the effort for each item.
Next.js in our own work
This website
next-levels.de runs on Next.js 16 with App Router, React 19 and TypeScript, in German and English. The content for blog, wiki and downloads comes from our CMS framework next-cms.
Self-hosted
We run the website as a Docker container on our own infrastructure with Coolify, not on Vercel. So we know self-hosting Next.js from our own daily work.
Tools and checks
The project calculator, the AI visibility check and the Security Check are part of the same Next.js application: forms, scans and reports run through server routes.
How a Next.js project runs
Cost and duration depend on scope. Our project calculator gives you a first range; the binding figure comes with the offer after the workshop.
First call
You describe the goal, the users and the systems you already have. We tell you straight away whether Next.js fits or whether another route is better.
Architecture workshop
We define the data model, interfaces and hosting and cut the scope into packages. The offer is based on that.
Delivery in iterations
We ship in short steps to a test environment, so you see every stage. Tests and code review are part of each step.
Go-live and operations
We deploy to your infrastructure or run the application for you. After that we handle updates and monitoring if you want.
Frequently asked Next.js agency questions
Your question isn't here? Ask us directly
What is Next.js?
Next.js is an open-source framework based on React for websites and full-stack web applications. It is maintained by Vercel, MIT-licensed and adds routing, data loading, server rendering and the build to React. The current version is 16, with the App Router and React Server Components.
What is Next.js suited for – and what not?
Next.js fits company websites, content-heavy platforms, shop frontends and portals with a public and a protected area – wherever content should be found. For an internal tool behind a login, a React single-page app is often enough. For a small site without its own development, a classic CMS is usually the shorter route.
Is migrating from the Pages Router to the App Router worth it?
The Pages Router is still supported, so nothing forces you. New React features such as Server Components are only available in the App Router, though. Both routers run side by side in one application. That is why we move route by route and start where new features are planned anyway.
Where do you host Next.js – only on Vercel?
No. Next.js runs on Vercel without further configuration, but it can also be self-hosted as a Node.js server or Docker container. According to the documentation, both support all features. Our own website runs as a Docker container on our own infrastructure. Which route fits depends on data protection requirements, load profile and your team.
Is Next.js good for SEO and AI search?
Next.js renders pages on the server or generates them statically in advance. Search engines and AI crawlers get finished HTML instead of an empty page that only takes shape in the browser. You maintain metadata, sitemap and structured data directly in the framework. That does not guarantee good rankings, but it provides the technical basis.
What does a Next.js project cost?
That depends on scope. The main cost drivers are the number of page types and views, the interfaces to CMS, shop or ERP, a custom design system and the requirements for tests and performance. Our project calculator gives you a first range; a binding offer follows after the workshop.
Sources
- Next.js documentation: introduction, App Router and Pages Router
- Next.js 16: release announcement
- Next.js 16.3: release announcement
- Next.js support policy: supported versions
- Next.js documentation: deployment and self-hosting
- Vercel documentation: Next.js on Vercel
- Next.js on GitHub: MIT licence
As of October 2026
Why nextlevels as your Next.js agency?
Server Components every day
We use the App Router and React Server Components on our own website every day. We know streaming and Suspense from operations, not from a demo repo.
SEO from the start
Core Web Vitals, structured data and the sitemap are part of the delivery, not an optional phase two.
TanStack for data interfaces
For tables, filters and forms with a lot of data we use TanStack Query and Table – with consistent patterns for cache and pagination.
Operations and updates
We deploy to your infrastructure or run the application for you. After go-live we handle updates and monitoring if you want.
Read on and check
Project calculator
A first cost range for your Next.js project.
AI visibility check
Checks whether Google and AI crawlers can read your page.
Web applications
Our service for portals and internal applications.
Hydration
How server HTML becomes an interactive interface.
Single-page application
What an SPA is and when it fits.
Projects
What we have built for clients – shops, apps and software.
Ready for your Next.js project?
Let's talk about your requirements – we'll get back to you within 24 hours with concrete next steps.
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