📙How-to

H Tag Hierarchy Design

최종 업데이트: May 6, 2026

Definition

H tag hierarchy design is the practice of arranging H1–H6 headers in semantic order to clarify page structure and improve LLM chunk extraction and accessibility.

Summary

H tags (H1–H6) are HTML semantic elements representing semantic hierarchy, not visual size. Use one H1 per page, H2 for main sections, and H3 for subsections without skipping levels. In the AEO era, LLMs treat H tags as chunk boundaries, so natural-language question-style headers increase AI citation potential.

Problems This Guide Solves

This guide answers the situation where "headers are used only for design (large text), and I don't know what matters for SEO/AEO." Using H tags as size-adjustment tools without meaning misses SEO opportunities, lowers LLM citation potential in AEO, and harms accessibility.

4 Roles of H Tags

1. Semantic Structure (Semantic HTML)

In HTML standards, H tags represent semantic section boundaries in a document. Both browsers and search engines interpret pages based on this structure. Visual size should be controlled separately with CSS.

2. SEO Signal

H1 and H2 are important on-page SEO signals. Google uses H tags to understand page topics and section content. Including core keywords in H1 strengthens page topic matching signals.

Google's John Mueller has noted there is no direct penalty for multiple H1s, but maintaining one H1 for topic clarity is the standard recommendation.

3. AEO/LLM Chunk Extraction

LLM-based answer engines process pages in chunks using RAG (Retrieval-Augmented Generation) architecture (see [How RAG Works] for details). H tags serve as boundary signals for this chunk splitting.

H2 header = entry point for an independent answer block (see [Creating Answer Blocks] for details)
Writing the first sentence below the header as BLUF makes that chunk an AI citation candidate
Natural-language question-style headers semantically match LLM queries directly

4. Accessibility

Screen reader users navigate page structure through H tag hierarchy and jump quickly to desired sections. Broken hierarchy significantly degrades the screen reader experience. WCAG 2.1 accessibility standards also require proper heading structure.

6 Rules for H Tag Hierarchy

1. One H1 Per Page

Use exactly one H1 per page. H1 represents the top-level topic of the page and is usually written almost identically to the title tag (see [Title Tag] for details). Multiple H1s make it harder for Google and LLMs to identify the page topic clearly.

2. Do Not Skip Hierarchy Levels

Correct order: H1 → H2 → H3 → H4
Incorrect order: H1 → H3 (skipping H2)

Using H4 after H2 or H4 directly after H1 violates HTML standards. It sends incorrect structure signals to both screen readers and search engines.

3. H2 = Main Sections (3–7 Recommended)

H2 divides the page into major sections. Too many H2s scatter the topic; too few lack structure. 3–7 is generally appropriate.

4. H3 = Subsections

Use H3 to classify sub-items within H2 sections. If H2 alone is sufficient, there is no need to add H3.

5. H4–H6 = Special Cases Only

H4 and below are needed for complex technical, legal, or academic content. For general blogs or marketing content, H4 and below are rarely needed.

6. Include Natural Keywords in Headers

Headers should reflect the core question or concept of that section. Write so keywords appear naturally, but avoid keyword stuffing. Natural-language question-style headers ("What impact do H1 tags have on SEO?") are often effective for LLM matching.

Relationship Between H Tags and Answer Blocks

Structuring H tags as questions and the first sentence below as a BLUF answer creates a structure optimized for LLM chunk extraction.

Good structure example:

## H2: What impact do internal links have on SEO?

Internal links serve four roles: crawl guidance, topic authority transfer, user navigation, and content hierarchy signaling.

(detailed explanation follows)

Bad structure example:

## H2: Internal Links

Before learning about internal links, you first need to understand what links are. Links are a basic component of hypertext...

(the core answer appears much later)

In the first structure, H2 and the first sentence together form a self-contained chunk that AI can cite as-is.

5 Steps to Design H Tag Hierarchy

Step 1: Define the Page's Core Question

Clearly identify the single main question this page answers. This becomes the H1 content.

Step 2: Write the H1

Write H1 almost identically to the title tag, though brand names are usually added only to the title (see [Title Tag] for details). H1 is the sentence that most clearly expresses the page topic.

Step 3: Divide Main Sections with H2

Split page content into 3–7 major sections and write an H2 for each. Reading only the H2 list should reveal the full page structure.

Step 4: Subdivide with H3

Use H3 when sub-items are needed under H2. H3 is a sub-classification of an H2 section.

Step 5: Validate Readability with a Table of Contents

Extract only H tags to create a table of contents and verify that page content flows logically. If the table of contents feels awkward, revise the H tag structure.

4 Common H Tag Mistakes

1. Visual Design First (Using H Tags for Size)

Using H tags instead of CSS styling to adjust font size is incorrect usage. Typical mistakes include multiple H1s or using H3 for large text then H2 for smaller text.

2. Keyword Stuffing

Excessively repeating the same keyword in headers violates Google guidelines and backfires.

3. Empty H Tags or Spacer Usage

Inserting empty <h2></h2> for visual spacing or using empty H tags as layout tools is a structural error.

4. Hierarchy Too Deep

Excessive use of H4, H5, and H6 in general content makes structure complex and reduces readability. Most content is sufficient with H1–H3.

H Tag Changes in the AEO Era

Stronger Natural-Language Question Headers

Traditional SEO included keywords in headers as noun phrases ("internal linking"). In the AEO era, natural-language question headers often match LLM natural-language queries more effectively ("How do internal links affect SEO?").

Using People Also Ask

Referencing "People Also Ask" in Google Search Console and search results when writing H2/H3 creates structure aligned with major queries from AI answer engines.

Converting CEP to H2

Expressing CEP (Category Entry Point) directly as H2 headers matches natural-language queries from users searching in that situation (see [Why CEP Matters More in the AEO Era] for details). Using prompt keyword analysis results in H2 writing is more effective (see [Prompt Keywords] for details).

Validation Tools

Chrome extension SEO META in 1 CLICK: View H tag list at a glance
Browser DevTools: Check H tag structure directly in the Elements tab
WAVE accessibility tool: https://wave.webaim.org — automatically detects H tag accessibility errors
Screaming Frog SEO Spider: Bulk audit for missing H1, duplicate H1, and H tag structure

Application in the Korean Market

H Tags on Naver Blog

Naver Blog automatically generates H tags when users select formats like "Title" or "Subtitle" in the editor. Because users cannot directly control HTML, content quality and channel trust (C-Rank) matter more than H tag optimization (see [How Naver SEO Works] for details).

Owned Sites

On owned sites such as WordPress, Cafe24, and Imweb, H tags can be fully controlled. In WordPress, select the heading level for each block in the block editor.

Korean Question-Style Headers

Korean question-style headers use polite question endings (equivalent to "is it…?", "how…?", "why…?"). This pattern naturally matches Korean AI search queries.

Frequently Asked Questions

Q. Does Google penalize two H1 tags?
A. There is no direct penalty. Google's John Mueller has said "multiple H1s are fine." However, since H1 represents the single top-level topic in HTML standards, one H1 is recommended for topic clarity.

Q. Must I include keywords in H2?
A. Natural inclusion is recommended, but forced insertion is unnecessary. Natural-language question headers are sometimes more effective for LLM matching, so accurately expressing section content takes priority over keywords.

Q. In blog posts, is H1 the blog title or the post title?
A. It depends on the CMS. In WordPress, the post title automatically becomes H1. The blog site name (logo/brand in the header) should be handled with other elements (<a>, <p>, etc.), not H1.

Q. What if I make H2 small with CSS and use multiple H1s?
A. This is bad for both SEO and accessibility. Control visual size with CSS and use H tags according to semantic hierarchy.