JavaScript SEO in 2026: What Still Matters

JavaScript SEO matured in 2024–2026. SSR vs SSG vs ISR is no longer a debate — each has its place. Here’s the framework.

What Google actually renders

Google’s second-wave renderer (deferred queue) executes JavaScript and re-indexes the rendered HTML. It is reliable. It is also slow — second-wave indexing can take days to weeks.

When to use SSR

• Content changes on every request (search results, dashboards).
• User-specific content.
• Freshness-sensitive content where first-wave indexing matters.

When to use SSG

• Marketing pages, blog posts, docs.
• Anything with a stable URL and infrequent changes.
• Anything where build-time HTML is fine.

When to use ISR

• Ecommerce product pages (price/availability change frequently).
• News articles (publish-time HTML, decay-managed revalidation).
• Large catalogs where SSR is too expensive.

The audit

1. Disable JavaScript in DevTools.
2. View source. Is your primary content present?
3. Enable JavaScript. Wait 5 seconds.
4. View again. Same content?
5. If yes to #2: you’re fine.
6. If yes to #4 but no to #2: you’re on second-wave indexing. Decide if that’s acceptable.

What doesn’t matter

The framework. Next.js, Astro, SvelteKit, Nuxt — they all ship acceptable JS SEO when configured correctly. The variable is the rendering strategy, not the framework.