Why do header tags matter so much to search? A lot of designers, developers, and programmers make the mistake of not putting relevant keywords into their header tags or even forgetting to write in header tags at all. This is disastrous for search engine optimization (SEO) and keeps sites from doing well with Google, Bing, and all the other search engines.

So what is a header tag? A header tag, more commonly referred to as an “h tag,” is a part of the hypertext markup language, or HTML. It tells the browser program (i.e. Internet Explorer, Firefox, Safari, etc.) and the search engines that it contains important information and sums up the following paragraph. There are multiple levels of header tags. h1 being the most important, followed by h2, h3, h4, h5, and h6.

Here you can see how our site’s CSS renders header tags.

Header 1

Header 2

Header 3

Header 4

Header 5

Header 6

h1 tags are styled by default at around 2 ems depending on your browser but you can easily change the styling of any header tag with css. For example if you wanted to make all the headers the same size, this is a bad idea from a usability standpoint, you would use the following in your CSS.

h1, h2, h3, h4, h5, h6 {

font-size: 1.8em;

}

While there are six different header tags, the h1 tag is the most important when it comes to SEO. It should contain relevant keywords and be similar to the title of the page. A common myth, something that I believed until recently, is that having multiple h1s negatively impacts your sites ranking. Multiple h1s are technically fine with Google as long as you don’t overdo it. Each h1 tag should be associated with a separate part of your site. Still, if possible try and stick with only one h1 tag per page, mainly because Bing still counts it as bad SEO and it could technically hurt your sites ranking.

While having relevant keywords in your header tag is critical, be careful to avoid keyword stuffing. Keyword stuffing is when you cram too many keywords into an element that google rates highly; like a titles, header tags, or meta tags. This is considered to be “blackhat SEO” and is a surefire way to get your site blacklisted. There is no published limit on text for a header tag so use your best judgement, keeping a header under two sentences is a good rule of thumb.

Quick Tips for Header Tag success:

1. Don’t skip any header levels. Going from an h1 to an h3 and skipping the h2 tag is not ok. Though it’s perfectly acceptable to go from an h2 to an h3 and back up to an h2.

2. Differentiate your header tags using CSS. They should all at least be one font size apart.

3. Use relevant keywords. Make sure your top search keywords are reflected in your header tags, especially the h1 tag.

4. Don’t use hyperlinks in your headings.

5. Never try to hide your headers, either with display: none or with a -9999px margin. This will immediately flag your site for review and might even earn you a Google blacklist.

One of the most common violations of SEO principles I see on a daily basis is having no h1 tags at all. Just by fixing the header tags and inserting relevant keywords, sites can jump two pages in Google search results. You can’t expect your page to succeed in search unless your underlying code is built with SEO in mind and one of the first places to look for improvement is your header tags.