What we check.

If your server or a firewall answers our crawler with 401, 403, 429 or 503, search engine crawlers are likely to get the same answer.

Whether robots.txt lets Googlebot and Bingbot crawl the page. Bing's index also feeds DuckDuckGo, Yahoo and Ecosia, so one rule can hide you from several search engines.

Whether smaller engines and specialist crawlers (Googlebot-Image, Applebot, DuckDuckBot and YandexBot) are blocked. A block here only warns.

Whether a noindex directive (in the page or the X-Robots-Tag header) keeps the page out of search results. A nosnippet directive only warns: the page can rank, but without a text snippet.

How much text is in the HTML your server sends. Search engines can render JavaScript, but often later and not always fully, so content in the HTML is the safe choice.

A sitemap at /sitemap.xml or listed in robots.txt, so crawlers can find all your pages.

Present, and 30–60 characters, so it is less likely to be cut short in search results.

Present, and 70–160 characters. Search engines often show it under your title, though they can choose other text from the page.

A rel="canonical" link. One that points to the page itself passes; one that points elsewhere warns, because it asks search engines to index a different address.

og:title, og:description and og:image, for a proper preview wherever the link is shared.

A single main heading that says what the page is about.

H2 and H3 subheadings that break the page into parts readers and search engines can follow.

Whether the title and the main heading are about the same topic, so the page sends one clear signal.

Enough specific text in the main content to cover the topic properly. Thin pages rarely rank for much.

Links to other pages on your site, which help crawlers find them and show how your pages relate.

Alt text on images, so search engines (and screen readers) know what each one shows.

Whether the page describes itself in JSON-LD, the structured data format Google recommends, and whether every block is valid JSON. A trailing comma is enough for a block to be ignored.

Organization or WebSite schema, ideally with sameAs links to your official profiles, so search engines can connect your brand across the web.

Schema for the page itself, such as Article, Product, LocalBusiness, Recipe or Event, which makes it eligible for rich results. Eligible is not guaranteed: search engines decide when to show them.

BreadcrumbList schema, which can show your site's structure in place of a bare address in search results.

Whether the page is served securely. HTTPS is a confirmed, if light, ranking signal, and browsers warn visitors about pages without it.

A viewport meta tag, without which phones show a zoomed-out desktop layout. Google indexes the mobile version of your pages.

How quickly the HTML arrives at our crawler. A slow server delays everything else on the page.

A lang attribute on the <html> element, so search engines know which language the page is in.

A byline, an author meta tag or author/publisher in the schema — who stands behind the content, which is part of what Google calls E-E-A-T.

A published or updated date, and whether it is within the last year.

Links from the main content to the external sources behind your claims.