HTML defines six levels of headings. A heading element implies all the font changes, paragraph breaks before and after, and any white space necessary to render the heading.

The heading elements are <H1>, <H2>, <H3>, <H4>, <H5>, and <H6> with <H1> being the highest (or most important) level and <H6> the least. They are used to help users and search engines to read and understand text.

For example, they act as signposts for the readers and make it easier for people to understand what a post or page is about.

Headings also define which parts of your content are important, and show how they're interconnected.

They are one of the key signals, along with many others, used by Google's search algorithm.

Here are some heading tags best practices.

Alt text is the written copy that appears in place of an image on a web page if the image fails to load on a user's screen.

This text helps screen-reading tools describe images to visually impaired readers and allows search engines to better crawl and rank your website.

cyberport.de has 17 images with a missing alt attribute.