SEO & webmaster guides

Practical guides written to be used, not skimmed — each one paired with a free tool so you can check your own site as you read.

What Is llms.txt? Format, Status and When to Use It What llms.txt is: the llmstxt.org proposal, its Markdown format, llms-full.txt, its honest status with Google and AI tools, and how to create a useful one. AI Visibility · 5 min read What Is a Backlink? A Plain-English Guide What a backlink is, how dofollow, nofollow, sponsored and ugc links differ, what Google treats as link spam, and how to earn backlinks that last. Backlinks · 7 min read SSL Certificate Errors: How to Diagnose and Fix Them Fix SSL certificate errors step by step: expired, self-signed, name mismatch, missing intermediate, untrusted CA, mixed content and HSTS, plus auto-renewal. Domain · 7 min read SEO Audit Checklist: A Practical Step-by-Step Guide A practical SEO audit checklist: crawlability, indexability, on-page tags, technical health, Core Web Vitals, structured data, internal links and AI readiness. SEO · 6 min read Schema Markup Guide: JSON-LD, Types and Testing A practical schema markup guide: JSON-LD vs Microdata vs RDFa, common types, required properties, @graph, testing tools, Google's guidelines and FAQ changes. SEO · 6 min read Robots.txt Guide: Syntax, Rules and Common Mistakes A practical robots.txt guide: RFC 9309 syntax, groups, Allow and Disallow, wildcards, the longest-match rule, sitemaps, and the mistakes that hurt SEO. Technical SEO · 6 min read Meta Tags for SEO: What Still Matters Which meta tags still matter for SEO: title, meta description, robots, canonical, viewport, charset, hreflang and Open Graph, plus the tags Google ignores. SEO · 7 min read The Keyword Density Myth: What Matters Instead Keyword density isn't a Google ranking factor. Learn where the myth came from, what Google says, what matters instead, and how to use a density check sensibly. Keywords · 5 min read How to Improve Website Speed and Core Web Vitals How to improve website speed: Core Web Vitals targets, lab vs field data, and fixes for images, caching, CDNs, fonts, JavaScript and server response. Website · 5 min read How to Find and Fix Broken Links on Your Site How to find and fix broken links: internal vs external dead links, soft 404s, when to update, redirect or remove, custom 404 pages, and what to fix first. Technical SEO · 6 min read How to Find Out Who Owns a Domain Name How to find who owns a domain using WHOIS and RDAP, what to do when data is redacted, how to reach registrars, and the clues in DNS and SSL certificates. Domain · 6 min read How to Find What CMS a Website Uses How to find what CMS a website uses: check the generator tag, asset paths, headers and cookies by hand, understand headless limits, and use a CMS detector. Website · 5 min read