This search engine optimization (SEO) guide explains how to optimize H3 tags for SEO.
Below, you’ll find a list of the top H3 tag optimization tips you can use to improve the rankings and traffic for your website based on best practices in digital marketing.
There’s also a section with additional resources that explain more about the fundamentals of H3 tags in HTML to help you create a better search engine optimization strategy.

Table of Contents
How To Optimize H3 Tags For SEO
1. Include Keyword Variations
The first way for how to optimize H3 tags in SEO is to use keyword variations, synonyms, and partial match keyword phrases of your main target keywords as well as semantically-related words for the associated subheaders.
You should avoid using the same exact match keywords that you’ve used in your higher-level header tags (H1 and H2) as this can lead to over-optimization or be seen as keyword stuffing). H3 tags are used to support the H2 subheadings by breaking them down into subcategories, so having the same keyword in the H3 doesn’t make logical sense to the user or search engine crawlers.
The examples below will help you better understand this H3 optimization strategy.
Suppose you’re targeting the keyword phrase, “Rhinoplasty Surgery Costs”. A good H2 and H3 header structure would be as follows because the H3 tags include keyword variations, synonyms, and semantically related words.
<h2>Rhinoplasty Surgery Costs</h2>
<h3>Average Nose Job Cost</h3> (Synonym)
<h3>Anesthesia Fees</h3> (Semantically-Related)
<h3>Surgical Facility Costs</h3> (Semantically-Related)
<h3>Post-Surgery Bills</h3> (Semantically-Related)
<h3>Nose Job Medication Prices</h3> (Semantically-Related)
<h3>Pricing Table for Rhinoplasty Plastic Surgery</h3> (Keyword Variation)
A bad example of using H3 tags for SEO that would be over-optimized and considered keyword stuffing can be seen in this example:
<h2>Rhinoplasty Surgery Costs</h2>
<h3>Average Rhinoplasty Surgery Costs</h3>
<h3>Anesthesia Cost for Rhinoplasty Surgery</h3>
<h3>Rhinoplasty Surgery Facility Costs</h3>
<h3>Post-Surgery Rhinoplasty Surgery Costs</h3>
<h3>Rhinoplasty Surgery Costs for Medication</h3>
<h3>Rhinoplasty Surgery Costs Table</h3>
2. Keep H3 Tags Under 60 Characters
Another best practice for H3 tag optimization is to use 60 characters or less for this HTML heading element. Any longer and it may dilute the topical relevance for SEO.
H3 tags are designed to be used as individual subheaders underneath the H2 headings in proper HTML markup. As a result, H3 subheaders should not be very long and are typically shorter than the H2 headings themselves.
For example, if an H2 heading is 60 characters in length, then the H3 tags should be 20 to 50 characters long for improved readability and SEO. But remember: this is a suggestion, not a hard and fast rule that can make or break your rankings in the SERPs. A common deviation from this recommendation is when an H3 subheader contains a question which often means the tag will have more characters than the associated H2 heading.
The key thing to remember here when constructing an H3 header tag is that it’s a subheader (or subcategory), not a sentence or paragraph. Therefore, the H3 tag should be brief and informative while only containing the necessary words for the user.
3. Use As Many H3 Tags As Necessary
Another important way to optimize H3 tags for search engine optimization is to use as many of these HTML headers as necessary to improve the user experience for the reader.
H3 header tags improve readability and comprehension for the visitor which enhances the user experience—a key ranking factor for SEO and search engine visibility.
Visitors who use desktop devices, mobile phones, and screen readers can more easily scan the information on a web page and navigate to the parts that include the details they’re looking for when the H3 tags are optimized well and used effectively.
For example, it’s common for a how-to article to include a single H2 tag followed by 5 to 10 H3 tags with a list of instructions for completing a task. It’s also completely normal for a web page to contain several H2 headings with multiple H3 header tags below each one to explain the relevant subcategories more in depth.
4. Don’t Repeat Keywords In H3 Tags
H3 tags are optimized best for SEO when you don’t repeat the same primary and secondary keywords in these HTML subheadings that are featured in the H1 and H2 heading tags.
Including the same target SEO keywords in an H3 tag will not make a measurable improvement in organic rankings. In fact, repeating your primary and secondary keywords in the H3 subheaders can have the opposite effect of lower search engine rankings by causing over-optimization.
A better strategy for SEO is to follow the first optimization tip in this guide which explained how to boost topical relevance for the page by including partial match keywords, synonyms, variations, and semantically-related words in the H3 tags.
5. Target Featured Snippets With H3 Tags
If you want to optimize your H3 tags for better search engine optimization, then you should structure them correctly to target Featured Snippets in search engines like Google, Yahoo, and Bing.
Featured Snippets are the extracts of a web page that are displayed at the top-ranking position in the organic search results to give users a quick answer to their query.
A common type of Featured Snippet is the list-style snippet that shows an ordered or unordered list. This snippet type appears in the SERPs for queries that match the user search intent for step-by-step guides, how-to instructions, and product lists. And, the H3 tags on the page are often pulled from the content for the Featured Snippet list.
An easy way to optimize your web pages for Featured Snippets is to make the first H2 heading on the page match the primary search query a user types into Google, Yahoo, or Bing to find the type of information your content is written about. A keyword research tool like Semrush, KWFinder, or SE Ranking can give you this data.
Next, you want to provide the answer to that query in the format of H3 tags directly below the H2 heading. The best practice for SEO is to include between 5 to 10 H3 tags with the subtopics that support the H2 heading above it. That’s because search engines typically display the first 5-8 items as a list in the Featured Snippet position; meaning, if your page only has between 1 to 4 H3 subheaders under the H2 tag, then it probably won’t get selected for this top-ranking position in the SERPs.
You can look at how this section of the web page is laid out to see an example of this SEO practice in action. I purposely structured it in a way to capture the Featured Snippets position for the primary keyword phrase: an H2 matching the search query followed by 5 H3 tags to be pulled for the Featured Snippets list.
Learn More About H3 Tags
The links below explain more about the H3 tag and how to use it correctly for better search engine optimization. Use these resources to expand your knowledge on the subject.
- Why Is H3 Tag Important for SEO?
- How to Optimize H3 Tags for SEO
- H2 vs H3 Header Tag In SEO
- H3 vs H4 Header Tag In SEO
Optimize H3 Tags In SEO Best Practices Summary
I hope you enjoyed this guide explaining how to optimize H3 tags for SEO.
As you discovered, there are many H3 tag optimization tips you can follow to improve your website’s search engine optimization, with the top SEO H3 tag best practices including the use of keyword variations, synonyms, and semantically-related words; keeping it under 60 characters in length, using as many H3 tags as necessary for the user, not repeating your main keyword phrases, and targeting the Featured Snippets position. Following these guidelines can help improve your overall SEO strategy for higher rankings and traffic.
