How it works
The H1 Checker audits the H1 (and the rest of the heading hierarchy) of any public web page, grades it A-F across 16 structural and content checks, and optionally compares it against the top-ranking competitors on Google for a focus keyword.
Single mode: paste one URL. We fetch the page through our proxy pool, parse the HTML, extract every heading H1-H6, and audit. The result shows a visual heading-hierarchy tree with per-level color tints (H1 blue, H2 purple, H3-H6 progressively lighter), an A-F grade, and severity-grouped findings.
Bulk mode: paste up to 10 URLs (one per line) on the Free plan. We queue them asynchronously and render a sortable table of every URL's grade. Click any row to expand the same per-URL detail view that single mode renders natively.
Focus keyword (optional but recommended): supply a focus keyword and the audit gains 3 keyword-targeting checks (keyword in H1, partial-match coverage, keyword missing). Without one, the audit covers only structural issues like H1 count, hierarchy hygiene, length bounds, and generic-phrase detection.
SERP comparison (single mode only, opt-in): enable the toggle and we look up the top 5 Google organic results for your focus keyword at your chosen location, proxy-fetch each one, and extract their H1s. You see exactly what the ranking pages wrote, side-by-side with yours. Each SERP comparison consumes 1 unit from your daily SERP quota (10 on the Free plan).
AI H1 rewrite CTA (single mode only, opt-in): click Get AI H1 rewrites and we return 3 H1 suggestions tailored to your focus keyword and your page's outline. Each is constrained to under 70 characters and forced to include the focus keyword. Each AI rewrite consumes 1 unit from your daily AI-tokens quota (50000 on the Free plan).
The 16-rule audit catalog: missing H1, multiple H1s, empty H1, empty other heading, H1 too long, H1 too short, hierarchy-level skip, H1 matches title (positive signal), H1 matches meta description (positive), focus keyword in H1 (positive), focus keyword partial match in H1, focus keyword missing from H1, low H2 coverage of subtopics, duplicate H1 text across bulk URLs, generic H1 phrasing, H1 in all caps.
What each part of the report means
- Grade (A-F)
- Rolls up the count and severity of detected findings. A is clean, no issues; F has at least one high-severity issue (missing H1, multiple H1s, hierarchy skip).
- Heading hierarchy tree
- Visual representation of every H1-H6 on the page in document order. Indented by level so you can spot hierarchy skips at a glance. H1 is blue, H2 purple, H3-H6 progressively lighter tints.
- H1 text
- The exact text of the page's H1 (or H1s if there's more than one). Click to copy.
- Page title and meta description (when present)
- Surfaced alongside the H1 so you can audit consistency. The audit checks whether the three communicate the same topic.
- Findings panel
- Severity-grouped (high / warn / info) list of every issue the catalog detected, with a one-line explanation per finding. The grade is a rollup of this list.
- SERP comparison panel
- Side-by-side table of YOUR H1 against the H1s of the top-5 Google results for your focus keyword. Helps you see exactly how your H1 stacks up.
- AI rewrites panel
- 3 alternative H1 suggestions returned by the AI rewrite CTA, each under 70 characters and including the focus keyword. Click any to copy.
- Bulk-mode table (bulk only)
- One row per submitted URL, with columns for URL, grade, H1 text, H1 length, finding count, and a "View" button that expands the row inline into the same single-mode detail view.
Frequently asked questions
What is an H1 tag and why does it matter for SEO?
An H1 tag (<h1>...</h1>) is the top-level heading of a web page, typically displayed as the page's main visible title. It tells both readers and search engines what the page is about in one line. The H1 is one of the strongest on-page topical signals: search engines weigh it heavily when deciding what query a page is relevant for. A clear H1 that matches the page's target keyword can meaningfully improve organic ranking; a weak, off-topic, or missing H1 leaves ranking signal on the table.
Can I have multiple H1 tags on one page?
HTML5 technically permits multiple H1 tags per page (one per <section> or <article>), and Google has stated publicly that multiple H1s do not directly hurt rankings. However, in practice, a single clear H1 remains the convention because it makes the topical signal unambiguous, simplifies accessibility (screen-reader users get one clear "this is the page" announcement), and matches how most CMS templates work. Our tool flags pages with multiple H1s as a warning, not an error: review whether the multiplicity is intentional and well-structured, or a CMS bug.
Should my H1 and my title tag be the same?
They should communicate the same topic, but they don't need to be identical. The title tag (the browser tab text and the SERP link headline) is optimized for click-through from search results: 50-60 characters, keyword forward, possibly with a brand suffix. The H1 is what readers see when they land on the page: it can be slightly longer, more conversational, and need not include the brand. Both should clearly answer "what is this page about?" using the same target keyword phrasing, but optimized for their distinct purposes.
What's the difference between H1, H2, and H3 tags?
- H1: the page's overall title. One per page is the convention.
- H2: top-level sections inside the page. The major chunks of your content.
- H3: subsections within an H2.
- H4, H5, H6: deeper nesting; rarely needed.
Headings form a hierarchy that should not skip levels: an H2 should not be followed by an H4 with no H3 in between. Our tool draws a visual heading-tree of your page and flags hierarchy skips as a finding.
How do I check the H1 of a page I don't own?
Paste any public URL above and click Audit H1. We fetch the page through our proxy pool, parse the HTML, and surface every heading from H1 through H6 in a visual tree. The audit catalogs 16 issues and grades the page A-F. For pages behind a login or paywall, you would need to view the HTML source manually (Cmd-Opt-U / Ctrl-U in most browsers) and search for <h1.
What does the "SERP comparison" feature do?
When you supply a focus keyword and enable SERP comparison (single mode only), we look up the top 5 Google organic results for that keyword at the location you pick, proxy-fetch each one, and extract their H1s. You see a side-by-side comparison of YOUR H1 against the H1s of the pages currently ranking for that exact query. This is the differentiator: instead of guessing "is my H1 good?" you see exactly what the ranking pages have written. Each SERP comparison consumes 1 unit from your daily SERP quota.
What does the AI rewrite CTA give me?
Click Get AI H1 rewrites and we send your existing H1, focus keyword, and page outline to a large language model that returns 3 alternative H1 suggestions. Each suggestion is constrained to under 70 characters, must include the focus keyword (when supplied), and must fit your page's actual content rather than being a generic template. This is opt-in and only available in single mode; each rewrite consumes 1 unit from your daily AI quota (50000 on the Free plan).
Can the H1 be longer than 70 characters?
Yes, technically there is no character limit on the H1. But for SEO practice we recommend under 70 characters because: shorter H1s read better as page titles for the user, they're less likely to wrap awkwardly across multiple lines on mobile, and they force you to be precise about your topic. Our audit flags H1s over 70 characters as a warning. Very short H1s (under 20 characters) get flagged as "too short" because they're rarely descriptive enough to convey what a page is actually about.