Technical SEO: the basics every developer should know
As a developer you influence SEO more than you think. Technical SEO is the foundation everything else rests on.
Meta tags
Essential on every page:
<title> — unique, 50-60 characters, keyword up front<meta name="description"> — 150-160 characters, call to action<link rel="canonical"> — prevent duplicate contentOpen Graph tags — for social media previews
URL structure
Short and descriptive:
/blog/app-development-cost (good)Avoid:
/blog/post?id=12345 (bad)Use kebab-case: words-with-hyphens
No trailing slash inconsistency
Redirect old URLs with a 301
Structured data (JSON-LD)
Add schema.org markup for rich results:
Organization — company information
BreadcrumbList — breadcrumb navigation
FAQPage — frequently asked questions
Article — blog articles
Product — products with price and reviews
Core Web Vitals
LCP (Largest Contentful Paint) — < 2.5s
Optimise hero images (WebP, preload)
Server-side rendering
INP (Interaction to Next Paint) — < 200ms
Minimise JavaScript
Use web workers for heavy computation
CLS (Cumulative Layout Shift) — < 0.1
Specify image dimensions
Reserve space for dynamic content
Crawlability
robots.txt — block only what must not be indexed
XML sitemap — every relevant page, generated automatically
Internal linking — every page at most 3 clicks from the homepage
404 page — a custom page with navigation back
Canonical tags — on every page
Performance headers
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
Referrer-Policy: strict-origin-when-cross-origin
Cache-Control: public, max-age=31536000, immutable (static assets)International SEO
hreflang tags — if you offer multiple languages
lang attribute —
<html lang="en">Tools for testing
Google Search Console — crawl errors, indexing
Google PageSpeed Insights — Core Web Vitals
Rich Results Test — structured data validation
Screaming Frog — technical site audit
This is exactly how we built virtuolab.dev — every check green. See how we work.