Which SEO basics do machines still depend on?

Each redirect hop is another request an AI client or crawler has to make before it reaches your content, and some give up. A single clean redirect is normal; a chain of them is latency you are adding to every visit. A page that does not answer at all is reported separately, as a refusal rather than a score.

What good looks like The URL answers directly, or through one clean redirect.

A Cache-Control, ETag, or Last-Modified header lets browsers and CDNs skip re-downloading an unchanged page — faster repeat visits, less server load, and a small hand to crawlers hitting you often.

What good looks like The page sends a Cache-Control, ETag, Last-Modified, or Expires header.

Serving the same content on both www and non-www (or http and https) splits ranking authority.

What good looks like All variants 301 to one preferred host.

A stray Disallow: / can hide your whole site from search; a missing robots.txt leaves crawling ambiguous.

What good looks like A valid robots.txt that allows your public pages and links to the sitemap.

A meta robots or X-Robots-Tag noindex removes the page from search entirely — often left on by mistake after launch.

What good looks like No noindex on pages you want found.

The canonical consolidates ranking signals onto the URL you want and resolves duplicate-content ambiguity. It counts whether you declare it as a link element or an HTTP Link header — Google treats both the same.

What good looks like A self-referencing canonical pointing to the preferred, on-domain URL — as a <link rel="canonical"> element or a Link: rel="canonical" response header.

Without a viewport tag a phone renders the page at a pretend desktop width and shrinks the result to fit, so none of your responsive breakpoints ever fire and the page arrives as an unusable miniature.

What good looks like A width=device-width viewport meta tag.

The title is the strongest on-page relevance signal and the first thing a search engine or an answer engine reads to know what a page is. A page with no title is unnamed to a machine.

What good looks like Every page has a unique, keyword-led title element.

It doesn't rank you directly, but it owns the search snippet and lifts click-through.

What good looks like A unique description roughly 70–160 characters — ~120–160 is the sweet spot for a full snippet.

One clear H1 states the page topic to crawlers and AI; none or several muddies the signal.

What good looks like A single H1 that states the page's topic.

A clean H1→H2→H3 structure is how crawlers, screen readers, and AI parse your content.

What good looks like Headings nest in order with no skipped levels.

When the title, H1, URL, and opening line agree on the topic, relevance is unambiguous.

What good looks like The main topic appears in the title, the H1, the slug, and the first paragraph.

Alt text powers image search, gives screen-reader context, and helps machines understand the page.

What good looks like Meaningful images carry concise, descriptive alt text.

OG tags control the preview card when your links are shared or cited — a growing discovery surface.

What good looks like og:title, og:description, og:image and og:url are all set, declared with property=.

A sitemap speeds discovery and indexing, especially for newer pages with few inbound links.

What good looks like A valid /sitemap.xml, referenced from robots.txt, whose URLs resolve.

A soft-404 (a 200 for a missing page) confuses crawlers and can get junk indexed.

What good looks like Unknown URLs return a true 404 with a helpful page.

A lang attribute and UTF-8 charset help engines, browsers and screen readers render correctly.

What good looks like A valid <!doctype html>, lang attribute, and UTF-8 charset.

hreflang serves the right language/region version and prevents duplicate-content confusion.

What good looks like Valid, reciprocal hreflang tags across your language variants.

Your favicon shows next to your result in search and in some AI answer interfaces — a small but real trust and brand signal.

What good looks like A <link rel="icon"> (or apple-touch-icon) pointing at a real icon.

A client-side <meta http-equiv="refresh"> redirect is slower than a server 301, can be ignored by crawlers, and is treated as a mild cloaking smell.

What good looks like Redirects use a server 301/302, not a meta refresh.