SEO Fundamentals for Modern Web Applications

SEO Fundamentals for Modern Web Applications

Search Engine Optimization ensures your content is discoverable, crawlable, and rankable. Modern SEO combines technical excellence with quality content.

Technical SEO Foundations

Crawlable: robots.txt, sitemap.xml, no orphan pages. Indexable: No noindex on important pages, canonical tags. Renderable: Server-side rendering or dynamic rendering for JS-heavy sites. Fast: Core Web Vitals. Secure: HTTPS. Mobile-friendly: Responsive, touch targets. Structured: Semantic HTML, heading hierarchy.

Core Web Vitals (Ranking Factors)

LCP (Largest Contentful Paint): <2.5s. INP (Interaction to Next Paint): <200ms (replaces FID). CLS (Cumulative Layout Shift): <0.1. Measured via CrUX (real users) and Lighthouse (lab). Optimize: Critical CSS, font loading, image optimization, JavaScript reduction.

JavaScript SEO

Google renders JS (two-wave: crawl → render). Challenges: Render budget, delayed content, client-side routing. Solutions: SSR/SSG (Next.js, Nuxt), Dynamic Rendering (prerender.io), Hydration optimization. Avoid: Hash-based routing, lazy-loaded critical content.

Structured Data (Schema.org)

JSON-LD (recommended), Microdata, RDFa. Types: Organization, WebSite, WebPage, Article, Product, FAQ, HowTo, BreadcrumbList, VideoObject, Event. Rich results: FAQ, How-to, Product snippets, Review stars. Test: Rich Results Test, Schema Markup Validator. Deploy via GTM or server-side.

Crawling and Indexing Control

robots.txt: Disallow paths, crawl-delay. Meta robots: noindex, nofollow, noarchive, nosnippet, max-snippet, max-image-preview. X-Robots-Tag: HTTP header for non-HTML. Canonical: Rel=canonical for duplicates. Pagination: rel=next/prev (deprecated but