Every HTML head tag that matters for SEO, with syntax, in one reference. The load-bearing ones are the title tag (~60 chars, the biggest on-page lever), rel=canonical, and the robots meta. Meta description drives click-through, not ranking. Meta keywords are ignored by Google and Bing, so skip them.
The HTML head tags that matter for SEO
What goes in your <head> tells search engines and AI how to title, describe and index the page. These are the ones worth getting right.
| Tag | Purpose | Syntax | Notes |
|---|---|---|---|
title | Page title in SERP and tab | <title>Page Title</title> | ~60 chars; the biggest on-page lever |
| meta description | Snippet under the title | <meta name="description"> | ~155 chars; drives CTR, not ranking |
rel=canonical | Consolidate duplicates | <link rel="canonical" href> | Self-reference or point to the preferred URL |
| meta robots | Index/follow control | <meta name="robots" content="noindex,nofollow"> | Controls this page only |
hreflang | Language and region | <link rel="alternate" hreflang="en-au"> | Needs matching return tags both ways |
| viewport | Mobile rendering | <meta name="viewport" content="width=device-width"> | Required for mobile-first indexing |
| charset | Character encoding | <meta charset="utf-8"> | Put it first in the head |
| Open Graph | Social and AI previews | <meta property="og:title">, og:image, og:description | Used by social platforms and some AI previews |
| Twitter Card | X share cards | <meta name="twitter:card"> | Falls back to Open Graph |
| meta keywords | Legacy | <meta name="keywords"> | Ignored by Google and Bing; skip it |
The load-bearing tags are title, canonical and meta robots. Open Graph matters for shares and increasingly for AI previews. More in header tags and on-page SEO.
Frequently asked questions
Do meta keywords still matter for SEO?
No. Google and Bing have ignored the meta keywords tag for years. Spending time on it does nothing; focus on the title, description and content.
What is the ideal meta description length?
Around 155 characters before truncation. Write it for click-through with the query and a reason to click; it influences CTR but is not a direct ranking factor.
Does the meta description affect ranking?
No, not directly. Google often rewrites it anyway. Its job is to win the click once you already rank, so treat it as ad copy for the result.
What does a canonical tag do?
rel=canonical tells search engines which URL is the preferred version when several URLs show similar content, consolidating ranking signals onto one page and preventing duplicate-content dilution.
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