Web page headings and SEO

How to use web page headings to improve Search Engine Optimisation

Headings should follow the HTML hierarchy for usability and accessibility reasons, this is covered elsewhere in this site.

However, where 'key words' and 'key phrases' are placed in the heading hierarchy can affect SEO.

Consider the following examples:

Example 1

Heading 1 - Dogs

Heading 2 - Cats

Heading 2 - Mice

In this example search engines will assume this page is primarily about "Dogs", of course it will register "Cats" and "Mice" but with less 'weight'.

Therefore the 'relevance' of this page to a user searching for "Dogs" is high.

The 'relevance' of this page to a user searching for "Cats" is not so as high.

Example 2

Heading 1 - Cats

Heading 2 - Dogs

Heading 2 - Mice

In this example search engines will assume this page is primarily about "Cats", of course it will register "Dogs" and "Mice" but with less 'weight'.

Therefore the 'relevance' of this page to a user searching for "Cats" is high.

The 'relevance' of this page to a user searching for "Dogs" is not so as high.

Example 3

Heading 1 - Cats and Dogs

Heading 2 - Mice

In this example search engines will assume this page is primarily about "Cats" and "Dogs".

Therefore the 'relevance' of this page to a user searching for "Cats and Dogs" as a key phrase is high.

The 'relevance' of this page to a user searching for "Cats" or "Dogs" is not as high as Example 1 or Example 2 as the relevance has been diliuted by the fact there are now two key words in the heading.