In one sentence
A meta description is a meta tag in the HTML <head> that contains a 120–160 character summary of a web page's content. It is used both in Google search-result snippets and to help AIs understand the page.
What does it look like in practice?
You write it inside <head> like this:
<meta name="description" content="An introductory guide that unpacks the definition of GEO (Generative Engine Optimization), how it differs from SEO, and the current state of the Japanese market using observed data from Smoke analysis.">
Once set:
- In Google search results: This description is displayed as a snippet underneath each article in the results
- In AI search: Claude / ChatGPT reference it as a page summary, improving comprehension when generating answers
- In SNS shares: It is used as a fallback for OG description
Why it matters
- Direct impact on CTR (click-through rate): A good meta description can lift CTR by 30–50%
- Used in AI page summaries: A good meta description makes the page easier for AIs to cite
- Minimal setup cost (about 5 minutes per page)
What makes a good meta description
| Condition | Description |
|---|---|
| 120–160 chars | Google's display limit. Anything longer is truncated |
| Includes the keyword | Contains keywords that match the search query |
| Encourages action (ideally) | E.g., "you'll learn ~" / "we explain ~" |
| Unique per page | Don't reuse the same text |
| Accurately reflects the page | "Clickbait" backfires |
Common mistakes
- Forgetting to set one: If absent, Google auto-extracts from the body, but often picks an unintended spot
- Same text on every page: Treated as duplicate content, lowers evaluation
- Keyword stuffing: Unnatural Japanese (or English) backfires
See also OG tag for more detail.