SEO

A plain-text file at the site root that tells crawlers which paths they may or may not fetch. Standardised in RFC 9309 and supported by every major search engine.

An XML file listing the canonical URLs of a site, with optional metadata about when each was last changed. The fastest way to tell a search engine what exists.

A sitemap of sitemaps. Used when a site has more than 50,000 URLs or wants to split sitemaps by content type for cleaner reporting.

Optional XML extensions that add image and video metadata to sitemap entries. Useful when media is loaded by JavaScript or hosted on a CDN that crawlers cannot reach by following links.

URLs are the most stable identifier on the web. Keep them lowercase, hyphenated, descriptive, and shallow. Treat them as a public API for your content.

HTTP redirects send a client from one URL to another. Use 301 or 308 for permanent moves, 302 or 307 for temporary ones, and never chain more than necessary.

A page that looks like a 'not found' message to a user but returns 200 OK to a crawler. Search engines treat soft 404s as a quality problem and often refuse to index them.

Every page must have an explicit, correct indexing policy — either implicit (default index, follow) on public pages, or an explicit noindex / X-Robots-Tag on staging, admin, thin, or private content. Get this wrong and you either disappear from search or expose what you didn't mean to.

Headings describe the sections of a page. They must form a nested outline, never be used for visual styling alone, and never skip levels.

Links from one page on a site to another. The strongest signal you control for telling crawlers and AI agents what a page is about and how important it is.

Machine-readable annotations that describe the content of a page using the schema.org vocabulary. JSON-LD is the format search engines and AI agents expect.

A short trail showing the page's position in the site hierarchy. Visible in the UI for users, marked up as BreadcrumbList JSON-LD for search engines.

An open protocol for telling participating search engines that a URL has changed. One HTTP request pushes Bing, Yandex, Naver, and Seznam to recrawl — Google does not participate.