The comprehensive on-page SEO checklist

On-page SEO — do these on every page.

15 categories · 80+ items · the complete on-page SEO spec for blog posts and service pages. Technical SEO (sitemaps, robots.txt, Core Web Vitals) is covered separately.
Save this as on-page-seo.md — every page-generation skill reads it before generating any page.
1
Head & Metadata
What Google indexes first
✓Title tag — 50–60 chars, primary keyword near the start.
✓Meta description — 150–160 chars, keyword + benefit + soft CTA.
✓Canonical URL set to prevent duplicates.
✓Open Graph — og:title, og:description, og:image (1200×630), og:url, og:type.
✓Twitter Card — summary_large_image, title, description, image.
✓Language attribute on <html> (e.g. lang="en").
✓Viewport meta tag for responsive rendering.
✓Favicon + apple-touch-icon.
✓Charset meta — <meta charset="utf-8">.
2
URL Structure
Clean, readable, keyword-forward
✓Short slug — under 60 chars.
✓Primary keyword in the slug.
✓Hyphens only — never underscores.
✓Lowercase only.
✓No stop words ("the", "a", "of") unless necessary.
✓Logical hierarchy — /services/[slug], /blog/[slug].
3
Headings
Structure for skimmers & bots
✓Exactly one H1 per page, contains primary keyword.
✓Logical H2 → H3 hierarchy — never skip levels.
✓H2s use supporting keywords + questions from the cluster.
✓No keyword stuffing — write naturally.
4
Copy & Body
Answer the query, fast
✓Primary keyword in the first 100 words.
✓Direct answer to the query in the first paragraph.
✓Length matches SERP average (within 20% of top-3).
✓Short paragraphs (1–4 sentences).
✓Readability — 8th–10th grade level.
✓Active voice preferred.
✓Bold key phrases — sparingly.
✓Bullets & numbered lists where appropriate.
5
FAQ Section
Every blog post
✓4–8 questions from SEMRush Questions tab + "People Also Ask".
✓Direct answers — 2–4 sentences each.
✓FAQ schema (JSON-LD) applied.
6
Images
Every image is a ranking signal
✓Alt text describes image + keyword where natural.
✓Filenames — descriptive, hyphens, e.g. emergency-plumber-toronto.webp.
✓WebP, compressed under 200 KB.
✓Width/height attributes specified — prevents CLS.
✓Lazy loading (loading="lazy") for below-fold.
✓Responsive srcset where needed.
✓Featured/hero image for social sharing.
7
Internal Links
Pass authority across the site
✓3–5 internal links per post.
✓Link to related blog posts & relevant service pages.
✓Descriptive anchor text — never "click here" or "read more".
✓Contextually placed in body copy.
✓Breadcrumbs on every page.
8
External Links
Cite authority, don't hoard it
✓2–3 external links to authoritative sources (.gov, .edu, major industry).
✓Relevant to the topic.
✓Open in new tab with rel="noopener".
✓rel="nofollow" for sponsored links.
9
Schema Markup
JSON-LD in <head>
✓Article schema on blog posts.
✓LocalBusiness schema — most specific subtype (Plumber, Dentist…).
✓Service schema on service pages.
✓FAQ schema wherever FAQ section exists.
✓BreadcrumbList schema on every page.
✓Organization schema site-wide.
✓Author/Person schema for bylines.
10
E-E-A-T Signals
Experience · Expertise · Authority · Trust
✓Author byline with name on every blog post.
✓Author bio with credentials (years, qualifications).
✓Link to author's dedicated page.
✓Published date displayed.
✓"Last updated" date when refreshed.
✓Real stories, numbers, opinions from the business voice file.
✓Cite authoritative sources.
✓About page with full company credentials.
✓Contact page — real address, phone, hours.
11
Accessibility
A11y signals = SEO signals
✓Semantic HTML5 — <header>, <nav>, <main>, <article>, <footer>.
✓ARIA labels on interactive elements where needed.
✓Color contrast meets WCAG AA (4.5:1 body text).
✓Focus indicators visible on interactive elements.
✓Alt text on all images (empty alt="" for decorative).
✓Descriptive link text.
✓Skip-to-content link for keyboard users.
12
Mobile & Responsive
Mobile-first indexing
✓Responsive layout (Tailwind handles this).
✓Touch targets minimum 48×48 px.
✓Body font minimum 16 px.
✓No horizontal scroll at any viewport.
✓No intrusive interstitials.
13
Social Preview
Shareable card
✓OG image optimized — 1200×630, under 1 MB.
✓Twitter Card image — 1200×600.
✓Compelling og:description — different from meta if valuable.
14
Conversion Elements
Capture the lead
✓Primary CTA above the fold.
✓Phone number with click-to-call (tel:).
✓Multiple CTA placements throughout the page.
✓Trust signals — reviews, ratings, licenses, years.
✓Testimonials with names (photos where possible).
✓Service-area coverage listed.
✓Business hours displayed.
✓Physical address with embedded map.
15
Long-Form Content
1500+ word posts
✓Table of contents with anchor links at the top.
✓Jump links for each H2.
✓Back-to-top button.
Point Claude Code at on-page-seo.md, then say "generate a blog post about X" — it will satisfy every item on this list automatically. That's the whole point.
80+ Items · 15 categories