- Hn tags (H1 to H6) structure your content: they help Google, generative AI engines and screen readers understand your page’s hierarchy.
- The “single H1” rule is an industry best practice, not a Google requirement: John Mueller confirmed Google’s systems handle multiple H1s without issue.
- The heading size limit does not come from Google but from SERP display: aim for around 60 characters for an H1, and short H2/H3 of 4 to 12 words.
- Never skip a level (H1 → H2 → H3), keep each heading unique, and never use an Hn tag for its font size alone.
Hn tags are your page’s headings and subheadings, ranked from H1 (most important) to H6. Used well, they help Google and AI engines understand your content and cite it.
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What is an Hn tag (H1, H2, H3…)?
An Hn tag is an HTML heading tag that structures and ranks the content of a web page. There are six levels, from H1 to H6, from most to least important. They are the headings and subheadings of your text, exactly like the title, chapters and subsections of a book.
The heading of this section is itself an H2 tag. The nesting logic is simple:
- H1 = the page title (only one, like a novel’s title)
- H2 = the main sections (the chapters)
- H3 = subsections within an H2
- H4 to H6 = deeper detail levels, rarely needed
In theory, Hn tags are invisible to the visitor: they take the form of HTML code, like <h1>Title</h1>. In practice, on a CMS like WordPress, each level comes with a default text size. This is precisely what leads so many sites to misuse them: you pick an H2 “because it’s the right size,” not because it’s the right structural level. More on that below.
Why do Hn tags matter for SEO?
Hn tags speak to three audiences at once: your readers, search engines and, more recently, generative AI engines. Each relies on your heading structure to understand your page.
They help Google understand your content
Google uses Hn tags to grasp the context and structure of your text. John Mueller confirmed that heading tags help better understand a page’s structure. The better Google understands what your content is about, the better it evaluates it. Today, the analysis goes beyond simple keyword matching: algorithms rely on natural language processing (NLP) to connect your headings to the page’s overall context.
They structure the reading experience
A visitor scans a page before reading it. Your Hn tags give them an instant reading map. The right test: read only your headings in order. If you understand the topic and the page’s flow from them alone, your structure is sound.
They make your page accessible
This is an often-forgotten criterion. Screen readers used by visually impaired people navigate from heading to heading. According to the WebAIM Screen Reader User Survey, 71.6% of screen reader users navigate by jumping between headings (source: WebAIM, see sources). An illogical hierarchy makes this navigation impossible, and Google increasingly values accessibility.
They make citation by AI engines easier
Answer engines like ChatGPT, Perplexity or Google AI Overviews split your pages into chunks to decide what to cite. A page well structured in Hn is easier to segment: each H2 defines a clear semantic zone, each H3 breaks down a sub-concept. A coherent structure makes your content extractable and citable, exactly what AI engines need.
Do you really need a single H1 per page? (what Google says)
Technically, no: Google does not require it. Asked how many H1s a page should have, John Mueller answered “as many as you want,” noting that Google’s systems handle multiple H1s on a single page without difficulty, a common pattern on the web (source: Google Search Central / Ask Google Webmasters, see sources).
So why do I still recommend a single H1? Because it works best for your readers, accessibility and search results display. A unique, clear page title, like a novel’s single title, removes any ambiguity about the main topic. The “single H1” rule is therefore a solid industry best practice, but not an algorithmic constraint. This distinction matters: it stops you from panicking when an SEO audit flags “multiple H1s” as a serious error, when it is not one in Google’s eyes.
What size for your H1, H2, H3 tags?
Google sets no official length for Hn tags. John Mueller even called the title’s character limit “an externally made-up metric.” The well-known 60-to-80-character recommendation comes from the SEO industry, not from Google.
So where does it come from? From display. Since 2021, Google can use your H1 to generate the title shown in the SERP, and that display is capped at about 600 pixels, roughly 50 to 60 characters before truncation (source: Webraketen analysis, see sources). It is this display constraint, not an algorithmic mandate, that justifies keeping your headings short. Here are my size benchmarks:
| Tag | Role | Recommended indicative size |
|---|---|---|
| H1 | Page title | ~60 characters (truncation risk beyond that if reused in SERP) |
| H2 | Main sections | 4 to 12 words, understandable on their own |
| H3 | Subsections | Short and descriptive, under the matching H2 |
| H4 to H6 | Deep details | Very short, use only when necessary |
Remember the principle rather than the exact number: a heading should be short enough to scan at a glance and explicit enough to describe its section without reading the body text.
How to optimize your Hn tags? The rules that matter
Beyond size, a few structural rules make the difference on your pages.
Never skip a level
Your Hn tags must always follow in order: one H1, then H2s, then H3s under each H2. Jumping straight from an H1 to an H3 creates a semantic break, detected by Google as well as screen readers. Like nesting dolls, each level fits inside the previous one.
Avoid isolated headings
If you open a lower level, add at least two. A single H3 under an H2 makes no sense: to segment is to create several parts, not one. A structure with an orphan H3 signals a shaky outline.
Keep each heading unique
Each Hn tag should be unique within the page, and ideally across the whole site. Two identical headings blur Google’s understanding of your topics.
Place your keywords without over-optimizing
Identify your keywords and weave them naturally into your headings, especially the main keyword in the H1 and secondary keywords in H2s and H3s. The mistake to avoid: repeating the same keyword in every heading. If you only read that keyword when scanning your outline, revise it.
Differentiate the H1 from the title tag
The title tag appears in search results, the H1 on the page. Without action from you, WordPress often reuses the page title as the title tag. Vary the wording: the title drives clicks, the H1 drives reading. Customize your title and meta description in your SEO plugin.
No Hn tag on the logo
An Hn tag represents a heading, so text. Never assign one to an image. Many WordPress themes place an H1 on the logo on the homepage: that is a structural error to fix.
How to audit your site’s Hn tags? (WordPress method)
Auditing your Hn tags lets you spot skipped levels, empty tags and mislabeled headings. Here is the method I apply on my clients’ sites.
- Display the page’s real structure. Use your browser’s inspector or an Hn tag testing tool to see the hierarchy as Google reads it, not as it appears on screen.
- Check order and uniqueness. Make sure there is no skipped level, no duplicated heading, and an H1 consistent with the page topic.
- Hunt down empty tags. An empty Hn tag (a heading with no text) is invisible on screen but exists in the code. It often appears after a mishandled line break in the editor.
- Spot the theme’s parasite Hn tags. On WordPress, sidebar or footer elements sometimes carry Hn tags imposed by the theme. Adapt the content to preserve order, or edit the theme code to remove them.
Good to know: faulty Hn tags are not a direct ranking penalty. They are, however, visibility you fail to gain. Prioritize the H1, which remains your page title and the strongest signal sent to Google and your readers.
Watch out for design tied to Hn tags
On WordPress, and especially with builders like Elementor, each Hn tag comes with a text size. Many sites therefore pick a tag for its appearance, not its function. This is the most common mistake I come across.
Hn tags serve to structure and rank content, never to set a font size. To enlarge or shrink text without touching the structure, use CSS or a formatting editor. Keep your headings for what they are: your page’s logical outline.
FAQ: your questions on Hn tags
How many H1 tags should a page have?
Technically, Google accepts multiple H1s without penalty. In practice, I recommend a single H1 per page: it is clearer for your readers, better for accessibility and more legible in search results.
What is the ideal size of an H1 tag?
Aim for around 60 characters. This limit does not come from Google but from SERP display: since 2021, Google can reuse your H1 as the displayed title, truncated around 600 pixels (about 50 to 60 characters).
What size for H2 and H3 tags?
Keep them short: 4 to 12 words for an H2, even shorter for an H3. The goal is for a reader to understand the section’s content just from the heading.
Can you skip a heading level, for example from H1 to H3?
No. Hn tags must follow in order. Skipping a level creates a semantic break detected by Google and makes navigation impossible for screen readers.
Should the H1 tag be identical to the title tag?
No, it is better to differentiate them. The title appears in search results and drives clicks; the H1 appears on the page and drives reading. Vary the wording and keywords between the two.
Do Hn tags influence my visibility in generative AI?
Yes. AI engines segment your pages by their heading structure to decide what to cite. A coherent Hn hierarchy makes your content more extractable. To measure whether ChatGPT, Gemini or Perplexity already cite you, a dedicated tool like Cockpyt AI is the most reliable method.
Can an Hn tag error penalize my rankings?
No, a poorly built hierarchy does not trigger a direct penalty. But it deprives you of visibility: Google understands your page less well, and you lose extraction and accessibility opportunities.
Sources
- Google Search Central / “Ask Google Webmasters” — John Mueller: “as many H1s as you want,” Google handles multiple H1s without issue. Relayed by Search Engine Journal and Ahrefs. ahrefs.com
- Webraketen, “SEO H1 – Why the Heading (Doesn’t) Matter,” April 2026 — origin of the ~60-character limit (SERP display ~600px), Mueller quote on title length. webraketen.space
- WebAIM, “Screen Reader User Survey” — 71.6% of screen reader users navigate by headings. Relayed by Arsh Infosystems, March 2026. arshinfosystems.com
- Advizup, “Balises Hn en SEO : le guide complet 2026,” April 2026 — H2 of 4 to 12 words, GEO structure and chunking. advizup.com
- 410-gone, “Comment optimiser vos balises H1, H2, H3,” April 2026 — Hn structure and extraction by generative AI. 410-gone.fr
