Technical SEO FAQ
10 questions answered.
What are Core Web Vitals?▾
Core Web Vitals are three Google-defined metrics for user experience. LCP (Largest Contentful Paint): main content load speed, good under 2.5s. INP (Interaction to Next Paint): responsiveness, good under 200ms. CLS (Cumulative Layout Shift): visual stability, good under 0.1. These are confirmed Google ranking factors.Read the Core Web Vitals guide →
How can I improve page speed?▾
Priority optimizations: (1) image optimization (WebP/AVIF, proper sizing, lazy loading), (2) reduce/defer unnecessary JavaScript, (3) CSS optimization (remove unused CSS, inline Critical CSS), (4) use a CDN, (5) improve server response time. Measure with Google PageSpeed Insights and address flagged items in order.Measure Core Web Vitals →
What is mobile-friendliness?▾
Mobile-friendliness means pages are optimized for smartphone viewing. Google uses Mobile-First Indexing (MFI), ranking based on mobile page versions. Requirements: responsive design, tap-friendly buttons (48px+), readable font size (16px+), and proper viewport configuration.
How should robots.txt be written?▾
robots.txt controls crawler access at the site root. Basic structure: User-agent: (target crawler) and Disallow: (blocked paths). Allow all: 'User-agent: * / Allow: /'. Block admin: 'Disallow: /admin/'. Include Sitemap: with your XML sitemap URL. Note: robots.txt is a request, not enforcement.
Is an XML sitemap necessary?▾
Not required but strongly recommended, especially for new sites, large sites, and complex link structures. Submitting to Search Console helps Google discover and index pages faster. Most frameworks auto-generate sitemaps. Include lastmod tags for frequently updated pages.Read the XML sitemap guide →
Is HTTPS mandatory?▾
Effectively yes. Google uses HTTPS as a ranking signal, and browsers show 'Not Secure' warnings for HTTP. Free SSL via Let's Encrypt makes cost near zero. When migrating, set 301 redirects for all pages and add HTTPS property in Search Console.
What is the difference between noindex and nofollow?▾
noindex: 'don't show this page in search results' — for admin pages, internal search, duplicates. nofollow: 'don't pass PageRank through this link' — for ad links, user-generated content. They serve different purposes and should not be confused.
What is the difference between 301 and 302 redirects?▾
301 means 'permanently moved,' 302 means 'temporarily moved.' The key SEO difference: 301 transfers link equity to the new URL, while 302 generally does not. Use 301 for domain changes, URL restructuring, and HTTP-to-HTTPS migration. Use 302 for temporary maintenance pages or A/B tests. Using 302 when you mean 301 loses accumulated page authority on the new URL.
How should I handle pagination for SEO?▾
For paginated pages (/page/1, /page/2...), link all pages with internal navigation and set unique titles/descriptions for each. Google discontinued rel="prev/next" as a signal in 2019. Current best practices: (1) keep all pages crawlable, (2) don't canonicalize all pages to page 1, (3) structure navigation so users can easily find what they need.
How do I handle multilingual SEO?▾
Three essentials: (1) Use hreflang tags to cross-reference language versions so the right language appears for each user. (2) Include language codes in URLs (example.com/en/, example.com/ja/). (3) Create unique titles, meta descriptions, and OGP for each language. Low-quality machine translations can hurt rather than help — start with high-quality translations for key pages and expand gradually.