Astro vs Next.js for Marketing Sites

If you are building a marketing site, blog, or documentation hub, use Astro. If you are building a product with auth flows, server actions, real-time data, or a complex interactive UI, use Next.js. I’ve built both, and sparkable.dev itself runs on Astro, which made the choice concrete for me. The performance gap on content-heavy pages is not marginal; it is fundamental, and it flows directly from how each framework thinks about JavaScript.

Why the JavaScript default matters

The biggest architectural difference between Astro and Next.js is not features; it is the assumption each one makes about interactivity.

Next.js ships the full React runtime on every page, because React hydration is the default. On a simple blog post or landing page, that means roughly 80-120KB of gzipped JavaScript that does almost nothing visible to the user. In a production benchmark comparing identical 30-post blogs, Next.js shipped ~85KB of gzipped JavaScript versus Astro’s ~8KB, a 90 percent reduction. The same test found Lighthouse Performance scores of 100 for Astro and 88 for Next.js SSG.

Astro ships zero JavaScript by default. Interactivity is opt-in through what it calls “islands,” meaning you explicitly flag a component as interactive and Astro hydrates only that piece of the page. Everything else is static HTML. This is not a limitation; it is a deliberate inversion of the React-first model.

How much does this gap matter for SEO and Core Web Vitals?

Quite a lot, in practice. Core Web Vitals (LCP, CLS, INP) are a confirmed Google ranking factor. According to the HTTP Archive Web Almanac 2025 Performance Chapter, only 48 percent of mobile pages and 56 percent of desktop pages currently pass all three thresholds. That means more than half of all mobile pages on the web are failing on metrics that correlate with both ranking and conversion. Reducing JavaScript shipped is one of the most reliable levers for improving those numbers.

I’ve watched this fail in practice. A startup I worked with had a WordPress marketing site that was serving ~350KB of JavaScript. After a migration to Astro, that dropped to 0-15KB, Lighthouse Performance jumped from 62 to 98, and LCP fell from 4.1 seconds to 1.0 second, a 96 percent JS reduction and a 4x LCP improvement. Organic traffic started recovering within six weeks of the migration.

The practical point: a slower site is not just a worse user experience. It is a ranking disadvantage that compounds month over month in competitive search categories. If your website is primarily a content asset, the framework you choose has a measurable effect on business outcomes. For more context on how website infrastructure decisions affect cost and ROI, see How Much Should a Startup Website Cost?.

Build speed and developer experience

Astro also wins on build speed for content-heavy sites. In a comparison of a 1,000-page documentation site, Astro built in 18 seconds versus 52 seconds for Next.js, roughly three times faster. At scale, that matters for CI/CD pipelines and incremental content publishing workflows.

On developer experience, the industry sentiment is clear. In the State of JS 2024, Astro ranked number one in Interest, number one in Retention, and number one in Positivity among meta-frameworks, with 94 percent of users saying they would use it again. In the Stack Overflow Developer Survey 2025, Astro ranked fourth most admired web framework with a 62.2 percent admiration rate (out of 23,678 respondents).

I’ve noticed in my own work that the file-based routing in Astro, combined with its .astro component syntax, makes content architecture cleaner. You can use React, Vue, or Svelte inside Astro islands where you need them, so you are not locked out of your existing component library. The “islands architecture” also means you can migrate incrementally: pull in React components where needed, leave the rest as zero-JS HTML.

Comparison table: Astro vs Next.js for marketing and content sites

When Astro wins

Astro is the right choice when the majority of your pages are content, not UI state. That includes:

• Marketing and landing pages. Thin interaction (a form, a modal) fits cleanly into islands. The rest is static.
• Blogs and editorial sites. Astro’s content collections handle Markdown and MDX natively. You get fast builds, typed frontmatter, and zero JavaScript overhead on post pages.
• Documentation sites. Astro Starlight (the official doc theme) built a 1,000-page site three times faster than the Next.js equivalent in benchmarks.
• Portfolios and small business sites. You do not need server actions or streaming React for a “contact us” page.

I chose Astro for sparkable.dev because the site is a hybrid: mostly static content and service pages, with a few interactive tools (assessment flows, calculators) that work fine as isolated React islands. The performance profile made the decision easy.

When Next.js wins

Next.js is the better choice when the product itself is the website. That means:

• SaaS dashboards. If your users are logged in and viewing personalized data, the React runtime is already justified.
• Auth-gated flows. Next.js App Router with server actions and middleware handles session management, redirects, and form mutations in a way Astro does not attempt to match.
• Real-time or streaming interfaces. Streaming server components, React Suspense, and websocket patterns all integrate cleanly in Next.js.
• Large React codebases. If your team already has a substantial Next.js component library and engineering practice, the switching cost is not worth it unless performance is a hard constraint.

Next.js usage at 20.8 percent of all Stack Overflow 2025 survey respondents reflects that most developers are building products, not just marketing sites. That is the right tool for that category of work.

Does Astro support server-side rendering?

Yes. Astro supports SSR with adapters for Cloudflare, Vercel, Node, and others. You can opt individual routes into server rendering with export const prerender = false. The default is static output. This means Astro is not limited to JAMstack scenarios; it is a practical choice for hybrid content sites that need a contact form API route or dynamic search page without rewriting everything in Next.js.

Frequently asked questions

Is Astro better than Next.js for SEO?

For content-heavy sites, Astro tends to produce better Core Web Vitals scores out of the box because it ships less JavaScript. Both frameworks support static output, canonical tags, and structured data, so on-page SEO fundamentals are achievable in either. The difference is that Astro’s defaults make it easier to hit good LCP and INP scores without manual optimization. A Lighthouse score of 100 versus 88 on the same content, across thousands of pages, adds up to a measurable ranking advantage over time.

When should I use Astro instead of Next.js?

Use Astro when your site is primarily content and the interactive elements are isolated and sparse. Marketing sites, blogs, documentation hubs, and portfolios are ideal Astro projects. Switch to Next.js when you need full-stack React capabilities: server actions, session-based auth, real-time updates, or a product UI that is deeply coupled to server state.

Does Astro support server-side rendering like Next.js?

Yes. Astro supports SSR through framework adapters (Cloudflare Pages, Vercel, Node.js, and others). Individual routes can opt into server rendering while the rest of the site remains statically generated. The API is not as feature-rich as Next.js App Router for complex server patterns, but for typical marketing site needs such as form APIs and dynamic search, it is sufficient.

Can Astro replace Next.js for a marketing website?

In most cases, yes. Astro handles the full marketing site use case well: static pages, blog, MDX, image optimization, RSS feeds, sitemap, and form endpoints via SSR routes or third-party APIs. If your “marketing site” also includes a customer-facing dashboard or auth-gated app, that is where Next.js remains a better fit. If those live on a subdomain or separate app, the marketing site can comfortably run on Astro.

How much JavaScript does Astro ship compared to Next.js?

In a production benchmark comparing identical 30-post blogs, Astro shipped ~8KB gzipped versus Next.js at ~85KB gzipped. That is roughly 90 percent less JavaScript. In a real-world WordPress-to-Astro migration, JavaScript dropped from ~350KB to 0-15KB, a 96 percent reduction.

Is Next.js overkill for a simple marketing site or blog?

Practically, yes. Next.js is designed around the assumption that you need React hydration, server actions, and middleware. Those features come at a bundle cost. For a marketing site where the heaviest interaction is a contact form and a mobile menu, you are paying a JavaScript tax with no corresponding benefit to users. Astro gives you the same static output quality with none of that overhead.

What is the difference between Astro islands and Next.js React Server Components?

Both are approaches to reducing client-side JavaScript, but from opposite starting points. Astro islands begin from zero JavaScript and let you add interactivity per component. React Server Components (RSCs) in Next.js begin from full React and let you mark components as server-only to avoid shipping them to the client. RSCs are more ergonomic when you have a large existing React app. Astro islands are cleaner when your baseline is a static content page. For marketing sites, islands win because the default state is “no JS needed.”

My recommendation

I’ve tested Astro in production on sparkable.dev and I’ve rebuilt client sites in both frameworks. For any site where content is the primary product, the answer is Astro. The performance advantage is real, the DX is better for content work, and the build times at scale are materially faster. Astro’s npm downloads grew from 360,000 to over 900,000 per week across 2025, more than doubling in a single year, because more teams are reaching this same conclusion.

The caveat is simple: if your marketing site is going to grow into a product, or if you are building on a team that is already deep in Next.js, the switching cost may outweigh the performance gains. In that case, invest in Next.js performance optimization through code splitting, lazy loading, and image optimization rather than a full framework change.

If you are starting fresh on a marketing site, blog, or documentation hub, start with Astro. You will get a faster site on day one with less engineering overhead.

If you are unsure which stack is right for your startup’s specific situation, I offer a free 30-minute consultation to talk through your requirements, your team’s existing skills, and what makes sense for where you are in the build. No pitch, just a straight answer. Book a free consultation at sparkable.dev/consult.