Meta tag checker

The tags that decide how a page is listed

A handful of tags in the <head> of a page do most of the work: the title tag, the meta description, the canonical, and the robots directives. This tool shows you exactly what a crawler is handed for one address.

What good looks like

• Title: roughly 25–60 characters. Past that Google frequently writes its own instead, usually from a heading on the page.
• Description: under 160 characters. It is not a ranking factor; it is the sentence that decides whether anybody clicks.
• Canonical: one, in the head. A canonical tag placed in the body is ignored outright, which means the page has none at all as far as Google is concerned.
• Robots: noindex keeps a page out of search. It is the correct tool for that job, and the wrong one to leave on by accident.
• Viewport: without it a page will not size itself to a phone, and most searches are on phones.

What we read, and what we do not

This reads the HTML the server sends, which is what Googlebot is given before it renders the page. On a site built with JavaScript a browser may show more than this, and the result says so when it detects one. A full audit re-renders a sample of pages in a real browser engine, because the difference between served and rendered HTML is where a surprising number of problems live.

Next: how to read an SEO audit report, or check what robots.txt allows.