These are the on-page signals search engines and social platforms actually read when they crawl or share a page — the same ones the Website Inspector's "SEO & Page Metadata" card checks for any URL you give it. Each one below explains what it is, why it matters, and what a good example looks like.
Title Tag
The title tag (<title>) sets the text shown in a browser tab, in Google's search results, and often in the preview when a link is shared. It has the single biggest influence on click-through rate of any on-page tag, because it is the first thing a searcher reads.
Aim for roughly 50-60 characters so it does not get cut off, put the most important keyword near the front, and make every page's title unique — a title reused across many pages tells search engines those pages are not clearly differentiated.
Meta Description
<meta name="description" content="..."> is the summary text search engines often show under your title in results. It has no direct effect on ranking, but a clear, compelling description meaningfully affects whether someone actually clicks your result over a competitor's.
Keep it around 150-160 characters, describe what the page actually delivers, and write a different description for every page — search engines will otherwise generate their own snippet from page content, which is rarely as persuasive.
Canonical URL
<link rel="canonical" href="..."> tells search engines which URL is the "real" version of a page when the same or very similar content is reachable at more than one address — for example with and without a trailing slash, with tracking parameters, or on both http:// and https://.
Without a canonical tag, search engines have to guess, and can split ranking signals across duplicate URLs instead of consolidating them onto one. Every page should point its canonical at itself unless it is intentionally a duplicate of another page.
H1 Heading
The <h1> is the main heading of a page and should describe what the page is about, both for readers skimming the page and for search engines building an understanding of its topic.
Use exactly one H1 per page. Zero H1s leaves the page without a clear topic signal; more than one dilutes it and can confuse screen readers, which rely on heading levels to build a page outline.
Open Graph Tags
Open Graph (og:title, og:description, og:image, and related <meta property="og:..."> tags) controls how a page appears when shared on Facebook, LinkedIn, WhatsApp, Slack and most other platforms that render a link preview card.
Without Open Graph tags, those platforms fall back to guessing from the page's title and a random image, which often looks broken or unappealing. At minimum, set og:title, og:description and og:image on every public page.
Twitter Card Tags
<meta name="twitter:card"> and related twitter:* tags control how a link looks specifically when shared on X (formerly Twitter). If they are missing, X usually falls back to Open Graph data instead, but adding both gives more precise control — for example choosing between a small thumbnail card and a large "summary_large_image" card.
Robots Meta Tag
<meta name="robots" content="..."> tells search engine crawlers how to treat this specific page — most commonly index, follow (index this page and follow its links, the default if the tag is absent), noindex (do not show this page in search results), or nofollow (do not pass ranking credit through this page's links).
noindex is the right choice for pages you do not want in search results at all — thank-you pages, internal search results, staging environments — rather than trying to block them with robots.txt, which only stops crawling, not indexing of a URL that is linked to from elsewhere.
XML Sitemap
An XML sitemap is a file — conventionally at /sitemap.xml — listing the URLs on a site that are worth crawling, optionally with metadata like when each was last updated. It does not force search engines to index every URL listed, but it makes discovery far more reliable, especially on large sites or for pages with few internal links pointing to them.
Referencing the sitemap's location in robots.txt with a Sitemap: line is the standard way search engines find it automatically.
Image Alt Text
The alt attribute on an <img> tag is a text description of the image, read aloud by screen readers and shown if the image fails to load. It is also one of the only signals search engines have for understanding what an image actually shows, since they cannot "see" the pixels.
Write alt text that describes the image's content or purpose in a few words — decorative images that carry no information can use an empty alt="" so screen readers skip them entirely, rather than leaving the attribute off completely.
JSON-LD Structured Data
JSON-LD (<script type="application/ld+json">) is a way to describe a page's content in a machine-readable format that search engines can parse directly — for example marking a page as an Article, Product, FAQPage or Recipe with structured fields like price, rating or publish date.
It is what powers many of the rich results you see in Google — star ratings, FAQ dropdowns, breadcrumbs — directly on the search results page. It does not guarantee a rich result will appear, but it is a prerequisite for most of them.
Internal vs External Links
Internal links point to another page on the same site; external links point to a different domain. A healthy mix matters for two reasons: internal links help both users and search engines discover and understand the relationships between your pages, while relevant external links to authoritative sources can add credibility and context for readers.
Pages that are only ever reached through external links, or that link out excessively without linking to anything else on the same site, are both worth a second look during an SEO review.