Seo Urls Routing

// GOOD — locale from route params
// [locale]/products/[id]/[slug]/page.tsx
export default function ProductPage({ params }: { params: { locale: string; id: string; slug: string } }) {
  // locale is dynamic
}

// BAD — hardcoded locale
const url = '/en-US/products/' + id; // Breaks for other locales

Slug Rules

• Lowercase only — blue-widget-pro-3000, never Blue-Widget-Pro-3000
• Hyphen-separated — wireless-headphones, not wireless_headphones or wirelessheadphones
• No special characters — no encoded characters, accents, or symbols in slugs
• Derived from product name/model — slugs should be human-readable and include the product identifier
• Stable — once a slug is published and indexed, do not change it without a 301 redirect from the old URL

Category URLs

Prefer path-based segments for subcategories:

// PREFERRED — path-based
/en-US/categories/electronics/wireless-headphones

// ACCEPTABLE — query-based (common in existing codebases)
/en-US/categories/electronics?type=wireless-headphones

Path-based URLs are better for SEO because:

• Search engines weight URL path words more than query params
• Easier to set up breadcrumbs and URL hierarchy
• Cleaner for users to read and share

Pagination

• Use ?page=N query parameter for paginated pages
• Page 1 canonical must NOT include ?page=1 — the canonical should be the base URL without the page param
• Subsequent pages should have a self-referencing canonical (?page=2 points to ?page=2)
• rel="next" and rel="prev" are not used by Google (dropped in 2019). Bing and some other engines still support them. Including them is low-effort and harmless, but don't rely on them for Google — proper canonical URLs and sitemap inclusion are more important for paginated content.

import { SITE_URL } from '@/config/site';

export async function generateMetadata({ params, searchParams }: Props): Promise<Metadata> {
  const page = Number(searchParams.page) || 1;
  const basePath = `${SITE_URL}/${params.locale}/categories/${params.slug}`;

  return {
    alternates: {
      canonical: page === 1 ? basePath : `${basePath}?page=${page}`,
    },
    other: {
      ...(page > 1 && { 'prev': page === 2 ? basePath : `${basePath}?page=${page - 1}` }),
      ...(hasNextPage && { 'next': `${basePath}?page=${page + 1}` }),
    },
  };
}

Search URLs

• Search pages are blocked by robots.txt: Disallow: /*/search/
• Also add noindex to search result pages as a fallback — if robots.txt is ever changed or removed, the noindex tag ensures these pages stay out of the index. Note: while robots.txt is active, Google cannot see the noindex tag (it blocks crawling entirely), so both protections do not work simultaneously.

// Search page (any router)
export const metadata: Metadata = {
  robots: { index: false, follow: true }, // noindex, follow
};

Why: Search results pages create near-infinite URL combinations, which wastes crawl budget and creates thin content.

Trailing Slashes

• Be consistent — pick one convention and enforce it site-wide
• Configure in next.config.js to enforce consistency:

// next.config.js
module.exports = {
  trailingSlash: false, // or true — pick one and stick with it
};

• If you change the trailing slash setting, set up redirects from old URLs to new ones

Dynamic Routes & Static Generation

• Use [id] and [slug] segments for dynamic content
• Use generateStaticParams to pre-render known pages at build time:

export async function generateStaticParams() {
  const products = await getAllProducts();
  return products.map(product => ({
    locale: product.locale,
    id: product.id,
    slug: product.slug,
  }));
}

• Use ISR (revalidate) for pages that update frequently (prices, stock):

export const revalidate = 300; // Regenerate every 5 minutes

Query Parameters & Filters

• Granular filter combinations should not be indexed — pages like ?color=red&size=large&weight=5kg should:
  • Have their canonical set to the base category URL (without filter params), AND/OR
  • Use noindex, follow to prevent indexing while allowing link discovery
• Useful single-filter pages can remain indexable — if the filter represents a real search intent (e.g. ?type=wireless), keep it indexed
• Sort parameters (?sort=price-asc) — the canonical should always point to the base URL
• UTM parameters — should be ignored by canonical (canonical never includes UTM params)

Common Technical Anti-Patterns

1. Missing locale prefix — every URL must start with /{lang}-{COUNTRY}/
2. Hardcoded locale strings — use route params, never hardcode en-US
3. Page 1 with ?page=1 — the canonical for page 1 is the clean URL without pagination
4. Changing slugs without redirects — if a product slug changes, 301 redirect the old URL
5. Uppercase in slugs — always lowercase
6. Indexable search pages — search results must be noindex
7. UTM params in canonicals — canonical URLs must never include tracking parameters