Snippets of HTML in a page's that describe the page to browsers, search engines, and social platforms without appearing in the visible content itself — things like the title, description, canonical URL, and social-share preview tags.

Do meta tags still work?

Some do, some don't. The title tag and canonical tag directly affect indexing and rankings; the meta description doesn't influence rankings but does affect click-through rate; the old meta keywords tag has been ignored by Google for over a decade.

How can I check what meta tags a webpage has?

View the page's source (or use a dedicated analyzer) and look inside the section — every meta tag lives there, whether or not it's actually doing anything useful.

What's a good meta description length?

Roughly 150–160 characters. Google doesn't enforce a hard cutoff and can rewrite your description anyway, but staying in that range keeps it from being truncated in most search results.

Meta Tag Analyzer: Check Title, Description & OG Tags Free

Q: What is the main purpose of a meta tag?

To pass information about the page to something other than a human reader — a search engine deciding how to index it, a social platform building a link preview, or a browser deciding how to render it.

What a meta tag actually is

A meta tag is a line of HTML that lives in a page's <head> — never visible on the page itself — that describes the page to something other than a human reader: a search engine deciding how to index it, a social platform building a link preview, or a browser deciding how to render it. A page can carry dozens of them, but only a handful actually do anything that affects SEO or how the page shows up when shared.

The meta tags that actually matter

Title tag — technically its own element, not a <meta> tag, but always grouped with them in practice. The single strongest on-page relevance signal a page carries, and the headline shown in search results.
Meta description — doesn't directly influence rankings, but it's the summary text under your title in search results, and a better one earns more clicks at the same ranking position.
Canonical tag — tells Google which URL is the "real" version when the same or similar content is reachable at more than one address. Get this wrong and Google may index the wrong copy or split ranking signals between duplicates.
Robots meta tag — controls whether a specific page can be indexed or its links followed, independent of what robots.txt says at the site level.
Viewport tag — not an SEO tag directly, but its absence breaks mobile rendering, which absolutely does affect rankings.

Open Graph and Twitter Card tags

A separate family of meta tags — prefixed og: and twitter: — controls how a link looks when shared on Facebook, LinkedIn, X, Slack, or iMessage: the preview image, title, and description shown in the card. These have zero effect on search rankings, but a missing og:image is the single most common reason a shared link shows a blank or wrong preview.

Meta tags aren't the only thing controlling how a page shows up in results, though — they handle the title and snippet text, while schema markup is the separate mechanism behind richer result types like star ratings and recipe cards. The two are complementary, not competing: a page can (and often should) carry both a well-written meta description and valid structured data, each doing a different job.

A bare page head versus a complete one

This is roughly what a default CMS template produces before anyone touches SEO settings — technically valid HTML, functionally almost blank to a search engine or a social platform:

<head>
  <title>Home</title>
</head>

"Home" as a title tells Google nothing about the page, there's no description for it to pull a snippet from, no canonical to disambiguate the URL, and no Open Graph tags — so a link shared to this page on any platform shows a blank preview card. Filled in properly for an actual product page:

<head>
  <title>Trail Running Shoes | TrailFoot Co.</title>
  <meta name="description" content="Shop trail running shoes built for
    mud, rock, and rain. Free returns, 30-day trial on every pair.">
  <link rel="canonical" href="https://trailfoot.example.com/shoes">
  <meta property="og:title" content="Trail Running Shoes | TrailFoot Co.">
  <meta property="og:description" content="Built for mud, rock, and rain.">
  <meta property="og:image" content="https://trailfoot.example.com/og/shoes.jpg">
  <meta name="viewport" content="width=device-width, initial-scale=1">
</head>

Every tag here does one specific job: the title and description control the search snippet, the canonical settles which URL is authoritative if this page is reachable more than one way (say, with and without a trailing query parameter), the three og: tags control the social share card, and the viewport tag is what makes the page render correctly on a phone at all. None of these six tags depend on each other — each is independently checkable, and missing any one degrades exactly the thing it's responsible for, nothing more.

Paste a URL into CheckSEO's Meta Tag Analyzer to see exactly which tags are present, missing, or misconfigured — no signup.

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5 common meta tag mistakes

Missing or duplicate title tags

Every page needs its own unique title. A CMS default that leaves every product page with the same generic title is one of the most common — and easiest to fix — issues an audit finds.

Meta description too long or missing entirely

Aim for roughly 150–160 characters. Longer gets truncated in search results; a missing description just means Google picks a snippet from the page itself, which is rarely as compelling as one you'd write.

No canonical tag, or one pointing to the wrong URL

Every page should have a self-referencing canonical unless it's deliberately a duplicate of another page. A canonical pointing at the wrong URL can quietly remove a page from Google's index in favor of the wrong one.

Missing Open Graph image

Without an og:image, a shared link often renders with no preview image at all, which noticeably hurts click-through when the link is shared on social platforms.

Accidental noindex in the robots meta tag

A page correctly crawlable per robots.txt can still be excluded from the index entirely by a stray <meta name="robots" content="noindex"> tag — often left over from a staging environment. This is the same class of mistake covered in confusing "disallow" with "noindex", just at the page level instead of the whole site.

The robots meta tag's other values

Most guides only mention noindex, but the robots meta tag accepts several distinct directives that each control a separate thing — worth knowing individually rather than treating the tag as a single on/off switch. nofollow tells crawlers not to pass ranking signal through the links on that specific page (different from a link-level rel="nofollow", which applies to one link rather than the whole page). noarchive stops Google from showing a cached version of the page. noimageindex keeps the page's images out of Google Image Search specifically, while leaving the page itself indexable. These can be combined in one tag, comma-separated — a page can be noindex, nofollow at once, common on internal search-results or filtered listing pages that shouldn't be indexed and shouldn't pass link equity onward either.

Why the same og:image sometimes shows up stale

Most social platforms cache the Open Graph data for a URL the first time it's shared, and don't re-fetch it on every subsequent share — which is why updating an og:image sometimes seems to have no effect: the platform is still serving the cached card from before the change. Facebook, LinkedIn, and X each provide their own debugger/inspector tool that force-refreshes their cache for a specific URL — worth knowing about specifically because it explains an otherwise confusing "I fixed it and nothing changed" situation. The fix on your end is correct; the cache just hasn't caught up yet.

Check your own page

CheckSEO's Meta Tag Analyzer reads a page's title, meta description, canonical, robots meta, and Open Graph/Twitter Card tags in one pass and flags exactly what's missing or misconfigured.

What Are Meta Tags, and Which Ones Actually Affect SEO?