Meta tags are HTML elements that provide metadata about a web page to search engines, social media platforms, and browsers. Getting them right is foundational to SEO, social sharing, and how AI systems understand your content. This reference covers every important meta tag with current best practices.
Essential HTML Meta Tags
| Tag | Purpose | Limit |
|---|---|---|
<title> | Page title shown in search results and browser tabs | 50-60 characters |
meta description | Summary shown below title in search results | 150-160 characters |
meta viewport | Controls responsive scaling on mobile | width=device-width, initial-scale=1 |
meta charset | Character encoding | utf-8 |
meta robots | Crawler instructions (index, follow, snippet control) | See robots section |
link canonical | Declares the preferred URL for duplicate content | Absolute URL |
link hreflang | Indicates language/region variants | ISO 639-1 + ISO 3166-1 |
Open Graph Tags
Open Graph (OG) tags control how your page appears when shared on Facebook, LinkedIn, Slack, Discord, and other platforms:
| Tag | Required | Best Practice |
|---|---|---|
og:title | Yes | Concise, compelling (60 chars max) |
og:description | Yes | Action-oriented summary (155 chars) |
og:image | Yes | 1200x630px, under 5MB |
og:url | Yes | Canonical URL of the page |
og:type | Yes | website, article, or product |
og:site_name | No | Your brand name |
Twitter Card Tags
| Tag | Value | Result |
|---|---|---|
twitter:card | summary | Small square image + text |
twitter:card | summary_large_image | Large image above text |
twitter:title | Page title | Falls back to og:title |
twitter:description | Summary | Falls back to og:description |
twitter:image | Image URL | Falls back to og:image |
Robots Meta Directives
The robots meta tag controls search engine behavior for individual pages:
index/noindex— Allow or prevent the page from appearing in search resultsfollow/nofollow— Allow or prevent following links on the pagemax-snippet:-1— Allow search engines to show unlimited snippet lengthmax-image-preview:large— Allow large image previews in search resultsmax-video-preview:-1— Allow unlimited video preview length
For AI search engines, max-snippet:-1 is particularly important — it allows AI systems to extract and cite longer passages from your content.
Common Meta Tag Mistakes
- Duplicate titles/descriptions: Every page needs unique meta tags. Duplicate tags confuse search engines about which page to rank.
- Missing og:image: Without an image, social shares look barren and get fewer clicks. Always provide a 1200x630px image.
- Self-referencing canonical missing: Every page should have a canonical tag pointing to itself (or to the preferred version if duplicates exist).
- Keyword-stuffed descriptions: Meta descriptions should read naturally. Keyword stuffing hurts click-through rates and may be ignored by Google.
- Ignoring max-snippet: Without
max-snippet:-1, search engines and AI systems may truncate your content in results.
Generate and validate meta tags with the Meta Tag Generator and Meta Tags Analyzer on WizlyTools.