This search engine optimization (SEO) guide explains H3 vs H4 header tag.
As you’ll discover below, H4 and H3 tags have separate purposes for search engines and website users. And knowing the difference between H3 and H4 tags for SEO will help you understand how to use each header HTML element correctly to grow your rankings and traffic.
There’s also a section with additional digital marketing resources that explain more about the fundamentals of H3 and H4 header tags to help you create the most effective search engine optimization strategy.
What Is the Difference Between H3 and H4 Tag?
The main difference between an H3 and H4 tag is that the H3 tag is a subheading used to break up the subtopics into further subcategories for the reader while the H4 tag is used to give more details about each subcategory.
H3 vs H4 Header Tag Comparison
The comparison table below shows the key differences between the H3 and H4 header tags in an easy-to-understand format. After the table, I’ll explain each factor individually.
| Parameter | H3 Tag | H4 Tag |
|---|---|---|
| Definition | The third-level heading in HTML structure that uses the <h3> header tag. | The fourth-level heading in HTML structure that uses the <h4> header tag. |
| Purpose | To cover important subtopics that fall under H2 subheadings. | To give further details about the information explained in an H3 subheading. |
| Optimal Character Limit | 60 or fewer | 40 or fewer |
| Number Per Page | Unlimited | Unlimited |
| Can It Be Optimized | Yes | Possibly |
| SEO Ranking Factor | Yes | Maybe |
What Is an H3 Tag?
An H3 tag is the level 3 header in an HTML document that uses the <h3> subheading code. The H3 tag is the third-largest heading tag and is used to denote a subtopic under an H2 header to be crawled by search engine spiders to confirm topical relevance.
H3 Tag Details
Purpose
The primary purpose of the H3 tag is to break up the content further into subtopics to enhance understanding for the user. The secondary purpose is to improve the topical relevancy signals for the keywords being targeted for SEO.
Optimal Character Limit
There’s no maximum character limit for the H3 header tag; however, the best practice for SEO and user experience is 60 characters or fewer. Typically, the text in the H3 tag is shorter than the associated H2 subheading because it defines a subtopic, but the H3 can be longer without any negative impact on SEO. Just keep in mind that having an overly lengthy H3 subheading tag can dilute the topical relevancy of this HTML element and make it harder for users to read.
Number Per Page
You can have as many H3 tags as you like on the page depending on the number of subtopics that are relevant to a particular section. Having multiple H3 header tags is not an issue for SEO and in some cases it’s preferred to have more H3 tags than H2 tags on the page. This guide is a classic example of this practice in action because the key sections require multiple subcategories for each subsection to explain the relevant factors for SEO.
Can It Be Optimized?
H3 tags can be optimized for search engines and users by including keyword variations, synonyms, and semantically-related words to help boost the topical relevancy without over-0ptimizing for your target keywords. Properly optimized H3 tags should describe the subcategories for the reader without containing exact match keyword phrases for the primary and secondary SEO keywords.
Is It a Ranking Factor?
The H3 tag is a ranking factor for SEO but has very little weight for on-page optimization. In other words, a poorly optimized H3 header will not make or break your keywords rankings. However, the lack of H3 tags on a page that requires it based on user search intent can reduce the perceived topical depth of the content which can lower rankings in the SERPs.
Search engines like Google, Yahoo, and Bing crawl the text inside the H3 headings to verify the topical depth and relevancy for relevant search queries, so you’ll want to make sure you include these header tags on pages that require a deeper level of explanation for the user.
What Is an H4 Tag?
An H4 tag is the level 4 header in an HTML document that uses the <h4> subheading code. The H4 tag is typically the fourth-largest of the heading tags and is used to denote a subsection of an H3 heading.
H4 Tag Details
Purpose
The purpose of the H4 tag is to give further details about the information explained in an H3 subheading. H4 headers go one more level deep to help improve understanding and comprehension of the subject matter.
Optimal Character Limit
There’s no maximum character limit for the H4 header tag; however, the best practice for SEO and user experience is 40 characters or fewer. Ideally, the H4 tag text should be shorter than the H3 tag it’s located under in the information hierarchy.
Number Per Page
You can have as many H4 tags as you like on the page depending on how deeply you need to explain the relevant items for an H3 subcategory. Having multiple H4 header tags is not an issue for SEO, but if you find yourself using too many of these subheaders, you may want to reassess the content structure because they’re not used much in standard HTML documents.
Can It Be Optimized?
It’s debatable whether H4 tags can be optimized for search engines. See the next point for more details.
Is It a Ranking Factor?
The H4 tag is not a ranking factor for SEO according to most industry professionals. However, some SEO experts have performed independent tests that indicate the H4 tag has some effect on keyword rankings in the SERPs. But keep in mind that this header is at such a low level in the HTML hierarchical structure that its impact on the search engine rankings is minimal at best.
Therefore, if you don’t need an H4 tag to help with readability or comprehension for the user, then you can safely ignore these header tags for SEO purposes. Optimizing or not optimizing the H4 tags will rarely make or break your keyword rankings in the SERPs.
Which Is Better H3 or H4?
The H3 is better than H4 for search engine optimization because the H3 tag is a stronger ranking factor for SEO. H3 tags describe the important subcategories for the page which search engine algorithms analyze for topical depth and keyword relevancy.
Can I Use H4 Instead of H3?
You can use H4 instead of H3 without any impact on the user; however, the H4 should be used under an H3 for proper HTML markup and defining the informational structure for search engines to crawl to understand the subcategories for the content.
Is It OK to Have H4 Before H3?
It is OK to have an H4 before H3 on the page because the order of HTML headings does not matter to the user. However, proper HTML structure for subheadings includes an H3 tag followed by an H43 tag in a web document.
Summary for H3 vs H4 Tag In SEO
I hope you enjoyed this guide on H3 vs H4 tag in SEO.
As you learned, the main difference between an H3 and H4 tag is that the H3 tag is a subheading used to break up the subtopics into further subcategories for the reader while the H4 tag is used to give more details about each subcategory.
However, both HTML elements are beneficial for your website when used together with their intended purposes in mind. Instead of just choosing the H4 or H3 header tag to optimize for SEO, you should follow the best practices for both elements to improve the user experience and on-page search engine optimization signals for higher rankings in the SERPs.
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