The Technical SEO Checklist Every New Site Needs Before Launch

Robots.txt. Sitemap. Canonical URLs. Schema markup. og:image. metadataBase. These are the 12 technical requirements we build into every site from day one — and why skipping any of them costs you in rankings, indexing speed, and organic traffic compounding over time.

Why Technical SEO Comes First

Content and backlinks are the accelerators of SEO. Technical SEO is the foundation. Without it, even excellent content may not be indexed properly, may not appear with the rich snippets that drive click-through, or may be split across multiple URLs and diluted. A site with a perfect technical foundation compounds every other SEO investment. A site with technical gaps works against every investment you make.

The good news: most technical SEO issues are one-time fixes. Build them correctly from launch and you don't have to revisit them.

1. robots.txt

A robots.txt file tells search engine crawlers which pages they're allowed to index. Without one, Google defaults to crawling everything — which may include admin pages, staging URLs, or internal search result pages you don't want indexed.

The minimum viable robots.txt for a Next.js site: allow all crawlers at the root, disallow /api/ routes (no need to index these), and declare your sitemap URL. Place this at the root of your domain and verify it's accessible at yourdomain.com/robots.txt before launch.

Common mistake: A leftover staging configuration that blocks all crawlers. This is the single most damaging technical SEO error — and one of the most common. Always verify your production robots.txt is not set to Disallow: /.

2. XML Sitemap

A sitemap gives Google a complete map of all indexable pages on your site, including when they were last modified. Without a sitemap, Google discovers your pages by crawling links — which may miss pages that aren't linked from anywhere prominent.

For Next.js App Router, use the sitemap.ts file convention. Generate the sitemap dynamically from your content so it stays current automatically. Declare the sitemap URL in robots.txt and submit it directly in Google Search Console after launch.

For sites with more than 500 pages, build a sitemap index that references multiple child sitemaps — one per content type (pages, blog posts, products, locations). This helps Google allocate its crawl budget more efficiently.

3. Canonical URLs

A canonical URL tells Google which version of a page is the authoritative one. Without it, Google may discover multiple URLs with identical or similar content — the trailing slash version and the non-trailing slash version, the HTTP and HTTPS versions, paginated pages — and split your SEO authority between them.

Every page needs a canonical tag pointing to its own URL (self-referential canonical). Pages with query parameters should canonical to the clean URL. In Next.js, set alternates.canonical in every page's metadata export.

4. metadataBase

Next.js requires a metadataBase URL to construct absolute URLs for Open Graph images, canonical links, and other metadata that needs a full URL. Without it, Next.js will warn in the console and some metadata may be constructed incorrectly.

Set this in your root layout.tsx: metadataBase: new URL('https://www.yourdomain.com'). This ensures every relative URL in metadata is resolved correctly against your production domain.

5. Title Tags (Per Page)

Every page needs a unique, descriptive title tag. Not "Home | Company Name" for the homepage — "Commercial Plumbing Services in [City] | Company Name." Title tags are both a ranking signal and the text displayed in search results, so they affect both visibility and click-through rate.

The format that works: Primary keyword phrase → secondary qualifier → brand name. Keep it under 60 characters to avoid truncation in search results.

6. Meta Descriptions (Per Page)

Meta descriptions don't directly affect rankings, but they affect click-through rate — which affects rankings indirectly. A well-written meta description tells the searcher exactly what they'll get on the page and why they should click your result over the others.

150–160 characters. Include the primary keyword. End with a call to action or a value statement. Make it specific to that page, not a generic brand description repeated across the site.

7. Open Graph Tags (og:title, og:description, og:image)

Open Graph tags control how your pages appear when shared on social media and messaging apps. Without them, social platforms pull whatever text and image they find first — often a logo, a random paragraph, or nothing at all.

Every page needs: og:title, og:description, og:image (at minimum 1200×630px), and og:type. The og:image is particularly important — posts with compelling images get dramatically more engagement than posts with no image or a generic one.

8. Structured Data (JSON-LD Schema)

Structured data tells Google what your content is about in a machine-readable format. For local businesses: LocalBusiness schema with name, address, phone, hours, geo coordinates. For articles: Article schema with author, publication date, headline. For products: Product schema with price, availability, reviews.

Correct structured data enables rich results in search — star ratings, prices, hours shown directly in the SERP. These rich results improve click-through rate significantly for eligible content types.

9. Heading Hierarchy (H1–H3)

Every page should have exactly one H1 — the primary topic of the page, including the target keyword. Subheadings (H2, H3) should describe the sections logically. Screen readers and Google's understanding of page structure both depend on a correct heading hierarchy.

The common mistake is using heading tags for visual styling instead of semantic structure — making something an H1 because it looks big, rather than because it's the most important heading on the page.

10. Image Alt Text

Every image needs an alt text attribute describing what the image shows. This serves two purposes: accessibility for screen readers, and a signal to Google about image content (images can rank in image search and contribute to page relevance signals).

Alt text should be descriptive and specific: not "image1.jpg" or "photo," but "commercial kitchen installation in progress at restaurant remodel." Include the relevant keyword where it naturally fits, but don't stuff keywords into alt text.

11. Core Web Vitals Baseline

Google's Core Web Vitals (LCP, FID, CLS) are ranking factors for search. A site that loads in 4 seconds ranks below an equivalent site that loads in 1 second, all else equal. Mobile performance matters even more than desktop — most local search happens on mobile.

Minimum targets: LCP under 2.5 seconds, CLS under 0.1, FID under 100ms. Measure these with the PageSpeed Insights API against your actual production URL — not in a local development environment.

12. HTTPS and www/non-www Consistency

Every page on your site should be served over HTTPS. All HTTP requests should redirect to HTTPS. All non-www requests should redirect to www (or vice versa, consistently). Every variation — http://, http://www., https://, https://www. — should resolve to exactly one canonical URL.

Inconsistent www handling is one of the most common causes of duplicate content issues and canonical confusion. Verify it with a simple redirect check on launch day and again after any domain or hosting changes.

The 30-Minute Checklist

Before any site goes live: verify robots.txt is accessible and correct, submit sitemap to Search Console, check that every page has a unique title and meta description, confirm canonical tags are present, validate structured data with the Rich Results Test, check og:image renders correctly in the social sharing debugger, run PageSpeed Insights on mobile, and confirm all four URL variants redirect to a single canonical HTTPS URL. This 30-minute checklist is the difference between a site that's ready for SEO and one that needs six months of remediation work.