What the meta description does
The meta description is a short summary of the page in its code. Search engines often show it as the text line under the title, where it gives people a reason to click.
How it works
The description sits in a meta tag in the head of the page. Visitors do not see it on the page, but they do in search results: there it often appears as the text under the page title.
<meta name="description" content="Tax advice for freelancers and small firms in Bristol. Online appointments available, first consultation free.">The description has no effect on ranking. It affects the click: a sentence that says exactly what the page offers is more convincing than a random excerpt. Without a description, search engines take any sentence from the page, often a menu item or the cookie notice. Even with one, Google sometimes adapts the text to the search query.
What matters
- 50 to 160 characters. Shorter wastes space. Longer texts get cut off; Google truncates by width in pixels, which is roughly 160 characters.
- One or two sentences that say what the page offers. Specific rather than general: service, place, audience, one advantage.
- One per page. If the code has several description tags, search engines take the first. Duplicates usually appear when both the theme and an SEO plugin add one.
- A different one for every page. The same description on every page helps none of them.
- True to the content. If the description promises something the page does not deliver, Google is more likely to replace it with its own text.
How to set it up
CMSs usually have a field for it per page, often called “meta description” or “SEO description”; in WordPress it comes with an SEO plugin. Some systems fill it automatically with the start of the text; for important pages such as the start page, write your own.
Without a CMS, the tag goes into the <head> of the page:
<meta name="description" content="…">Check the page source to make sure it appears only once.