SEO Checklist for Developers: 50 Essential Points

Why Developers Need SEO Knowledge

Most SEO guides are written for marketers. But developers control the HTML, server config, and page speed — the technical foundation that determines whether SEO efforts succeed or fail.

This checklist covers everything a developer should verify before deploying a website.

Meta Tags (10 checks)

1. **Title tag exists** and is 30-60 characters

2. **Meta description** exists and is 120-160 characters

3. **Canonical URL** points to the correct page

4. **Viewport meta** tag is set for responsive design

5. **Language attribute** on html tag (`lang="en"`)

6. **Charset** is UTF-8

7. **Favicon** exists (ICO + SVG)

8. **robots meta** is index,follow (unless intentionally noindex)

9. **No duplicate** title or description tags

10. **Open Graph + Twitter Card** tags for social sharing

Content Structure (8 checks)

11. **Exactly one H1** tag per page

12. **Heading hierarchy** — H1 → H2 → H3 (no skipping)

13. **No empty headings** — every heading has text

14. **Word count** above 300 for content pages

15. **Alt text** on all meaningful images

16. **Internal links** to related pages

17. **Descriptive anchor text** (not "click here")

18. **Structured data** (JSON-LD) for rich snippets

Performance (10 checks)

19. **Gzip/Brotli compression** enabled

20. **Cache-Control headers** set for static assets

21. **Images lazy loaded** below the fold

22. **Images in WebP/AVIF** format

23. **Critical CSS** inlined or preloaded

24. **JavaScript deferred** or async

25. **No render-blocking** resources

26. **Font-display: swap** on custom fonts

27. **Preconnect** to critical third-party domains

28. **Total page weight** under 1.5MB

Security (8 checks)

29. **HTTPS** everywhere

30. **HSTS header** with max-age ≥ 31536000

31. **CSP header** without unsafe-inline

32. **X-Frame-Options** set to DENY

33. **X-Content-Type-Options** nosniff

34. **Referrer-Policy** strict-origin-when-cross-origin

35. **No X-Powered-By** header exposed

36. **Cookies** have HttpOnly + Secure + SameSite flags

Technical SEO (8 checks)

37. **robots.txt** exists and allows important pages

38. **sitemap.xml** lists all important URLs

39. **No redirect chains** (max 1 hop)

40. **301 redirects** for permanent URL changes (not 302)

41. **Clean URLs** — lowercase, hyphens, short

42. **Hreflang tags** for multi-language sites

43. **Canonical doesn't point to 404**

44. **No noindex on important pages**

Accessibility (6 checks)

45. **Form labels** on all inputs

46. **Skip navigation** link

47. **ARIA landmarks** (header, nav, main, footer)

48. **Sufficient color contrast** (WCAG 4.5:1)

49. **Keyboard navigable** — all interactive elements focusable

50. **Heading hierarchy** (also an SEO factor)

Automated Checking

Run all 50 checks automatically with [SEO Snapshot](/) — paste any URL and get results in seconds with copy-paste fix code.

FAQ

**Q: Should developers learn SEO?**

A: Yes. 60% of SEO issues are technical — only developers can fix them properly.

**Q: What's the single most impactful SEO fix?**

A: Adding proper title tags. Pages without titles can't rank.

**Q: How do I test SEO before deploying?**

A: Use SEO Snapshot on your staging URL, or run Lighthouse in Chrome DevTools.