A Pre-Launch SEO Checklist for CSR Apps #

The cheapest time to fix a JavaScript SEO problem is before launch, while you can still change rendering strategy without a migration. This checklist walks the four things that determine whether a client-rendered app is indexable — rendering, metadata, crawlability, and Core Web Vitals — and turns each into a concrete pre-launch verification.

Step-by-step checklist #

1. Verify content is in the rendered DOM for every template. Inspect one URL per template and confirm the rendered HTML contains the heading and body, not just the shell.

   • Product/detail template renders content in the DOM
   • Listing/category template renders content in the DOM
   • Article/content template renders content in the DOM

   ❌ Rendered HTML: 
     → content depends on the render queue
   ✅ Rendered HTML: full 
    + body + JSON-LD present

2. Confirm per-route metadata. Titles, descriptions, canonicals, and Open Graph tags must be correct in the rendered head for each route — coordinate with dynamic metadata management.

   • Unique <title> and meta description per route
   • Self-referencing <link rel="canonical"> per route
   • Open Graph and Twitter tags resolve in social debuggers

3. Make routes crawlable. Real <a href> links, a submitted sitemap, and a robots.txt that does not block bundles or APIs.

   • Navigation uses crawlable <a href> links
   • Sitemap generated from the route source and submitted
   • robots.txt allows JS/CSS/API resources the render needs

4. Hit Core Web Vitals targets. LCP, CLS, and INP within thresholds on representative templates.

   • LCP under 2.5s on a mid-tier device
   • CLS under 0.1, including during hydration
   • No render-blocking scripts in the head

Validation #

• GSC URL Inspection rendered HTML passes for one URL per template.
• Rich Results / OG debuggers show correct metadata.
• Lighthouse SEO category at or above 0.95 on each template.
• Sitemap submitted and read without errors in Search Console.

Reference #

Launch gate (all must pass):
[ ] Rendered DOM has content for every template
[ ] Per-route title, description, canonical, OG tags correct
[ ] Crawlable  nav + submitted sitemap + permissive robots.txt
[ ] LCP < 2.5s, CLS < 0.1, no render-blocking head scripts

Frequently Asked Questions #

What is the most important SEO check before launching a CSR app? Confirm that primary content appears in the rendered HTML for every template — product, article, listing — using Search Console URL Inspection or a JS-rendering crawl. If content is missing from the rendered DOM, nothing else on the checklist matters.

Do I need a sitemap for a client-side rendered app? Yes. A sitemap helps crawlers discover routes that may otherwise depend on JavaScript navigation. Generate it from the same route source your app uses, and submit it in Search Console before launch.

Related #

• Client-Side vs Server-Side Rendering for SEO — choosing the rendering mode this checklist verifies.
• SEO Audit Workflows for Client-Side Apps — the tools to run each check.
• Why Google Indexes Blank Pages for React Apps — the failure this checklist prevents.

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