SPA vs MPA vs SSG: which architecture to pick

Compare the three dominant web architectures and choose the one that fits your project best

9 min

SPA, MPA and SSG represent three fundamental approaches to building web applications. Each has direct implications for performance, SEO, user experience and development costs. Understanding the differences is essential for making the right architectural decision.

It’s not about choosing the most modern or popular option, but the one that best solves your project’s specific requirements. In this guide we analyse each architecture with its strengths, limitations and real use cases.

What is a SPA (Single Page Application)?

A SPA loads a single HTML page and dynamically updates content using JavaScript without reloading the browser. Frameworks like React, Vue and Angular are the most common choices. The experience is fluid and similar to a native application.

The server delivers a minimal HTML shell and a JavaScript bundle that handles all navigation and rendering on the client. Transitions between views are instant because there are no full-page requests to the server.

  • Fluid app-like experience with no page reloads
  • Ideal for interactive applications: dashboards, SaaS tools, editors
  • Requires JavaScript to function; without JS, no content is visible
  • Limited native SEO (requires additional SSR or pre-rendering)

What is a MPA (Multi Page Application)?

An MPA is the traditional web architecture: each URL corresponds to a complete HTML document generated by the server. When navigating between pages, the browser makes a request to the server and receives fresh HTML. WordPress, Rails and most CMS platforms work with this model.

MPAs offer excellent SEO naturally because each page is a fully indexable document. Initial performance (Time to First Byte) depends on the server, but there are no large JavaScript bundles blocking rendering.

  • Native SEO: every page is a complete, indexable HTML document
  • Does not rely on JavaScript to display content
  • Ideal for content-heavy sites: blogs, media, catalogues
  • Page transitions involve a full browser reload

What is SSG (Static Site Generation)?

SSG generates all pages as static HTML files at build time. The result is served from a CDN with no dynamic server required. Tools like Astro, Next.js (static mode), Hugo and Eleventy use this approach.

By serving static files, performance is maximised: there is no per-request server processing, and global CDNs ensure minimal loading times from any location. It’s the ideal option for sites whose content does not change with every visit.

  • Peak performance: static files served from a CDN
  • High security: with no exposed dynamic server, the attack surface is minimal
  • Very low hosting costs (Netlify, Vercel, Cloudflare Pages)
  • Not suited for highly dynamic or real-time user-personalised content

Direct comparison: performance, SEO and UX

Perceived performance varies by architecture. SPAs offer smooth navigation once loaded, but initial load can be slow if the bundle is large. MPAs depend on server speed for each page. SSGs are the fastest for initial load thanks to static pre-rendering.

For SEO, MPAs and SSGs have a clear advantage: they deliver complete HTML to crawlers. SPAs need additional configuration (SSR, pre-rendering, dynamic rendering) to be indexed properly. For user experience, SPAs excel in interactivity, while MPAs and SSGs are superior in time to first paint.

  • Load performance: SSG > MPA > SPA (without SSR)
  • Native SEO: MPA = SSG > SPA
  • Interactivity: SPA > MPA with partial JS > SSG with selective hydration
  • Hosting cost: SSG (minimal) < MPA (server) < SPA (server + CDN + API)

Hybrid approaches: the best of every world

The evolution of the web ecosystem has blurred the boundaries between these architectures. Frameworks like Next.js, Nuxt and Astro allow combining SSG, SSR and SPA behaviour within the same project, choosing the rendering strategy on a per-page basis.

Astro, for example, generates static pages by default but lets you add islands of interactivity (React, Vue, Svelte) only where needed. Next.js can pre-render static pages, generate others on the server and function as a SPA in interactive sections. This hybrid approach is increasingly the norm in modern projects.

  • ISR (Incremental Static Regeneration): regenerates static pages on demand without a full rebuild
  • Islands Architecture: static pages with isolated interactive components
  • Streaming SSR: server rendering sent progressively to the browser

When should you use each architecture?

The choice depends on the project type, performance and SEO requirements, and the level of interactivity needed. There is no universal answer, but there are clear patterns that work.

  • SPA: interactive web applications where app-like experience is the priority (dashboards, internal tools, editors)
  • MPA: content-heavy sites with strong SEO needs where interactivity is secondary (blogs, media, documentation)
  • SSG: sites with infrequently changing content where peak performance is key (landing pages, corporate websites, documentation)
  • Hybrid: projects that combine static content with interactive sections (ecommerce, platforms with public and private areas)

Key Takeaways

  • SPA delivers maximum interactivity but requires additional work for SEO
  • MPA is the natural choice for content-heavy sites with strong native SEO
  • SSG combines peak performance with minimal hosting costs
  • Modern frameworks enable hybrid approaches that blend the best of each architecture
  • The right choice depends on the project type, not the framework’s popularity

Need help choosing your project’s architecture?

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