On-Page SEO
On-Page SEO checks the content elements on the HTML page itself: title tag, meta description, headings, images, and body copy. Weight: 15%.
Details
Title tag
The <title> tag is the most important on-page SEO element. It appears as the blue headline in Google search results and in browser tabs.
Optimal length: 30–60 characters. Shorter titles waste relevance signals; longer titles get cut off in SERPs. Every page must have exactly one unique title tag containing the primary keyword.
A missing title is a critical issue (−20 pts). A title outside the optimal length range is a warning (−10 pts).
Meta description
The meta description appears as the snippet below the title in search results. It does not directly affect rankings, but a compelling description improves click-through rate (CTR).
Optimal length: 120–160 characters. If missing, Google auto-generates a snippet from page content — often less relevant than a hand-crafted description. A missing or too-short meta description is a warning.
Heading structure (H1–H6)
Headings create a logical document outline. Each page should have exactly one H1 containing the primary topic. H2 and H3 headings help Google understand the page's subtopics and improve readability.
Missing H1 is a critical issue. Multiple H1s, skipping heading levels (H1 → H3), or a flat structure (no H2/H3 after H1) are warnings. The audit reports the full heading distribution (h1: N, h2: N, h3: N, etc.).
Images and alt text
Alt text (the alt attribute on <img> tags) describes an image to search engines and screen readers. Images without alt text miss an opportunity to rank in Google Images and reduce accessibility score.
The audit counts total images and images missing alt text. A high ratio of missing alt text triggers a warning.
Content length and DOM size
Thin content (fewer than ~300 words) is often insufficient to rank for competitive queries. The audit counts words, paragraphs, and DOM nodes.
A very large DOM (excessive node count) can slow down rendering and is flagged. Pages with extremely bloated DOM may receive a critical issue.
Top keywords
The audit extracts the most frequently used words on the page (excluding stop words) and reports them with their density percentage. This gives a quick view of what Google is likely to consider the page's primary topics.
Metrics
| Metric | Description |
|---|---|
| Title | The full text of the page title tag. |
| Title length | Character count of the page title. Optimal: 30–60 chars. |
| Meta description | The full text of the meta description tag. |
| Meta description length | Character count of the meta description. Optimal: 120–160 chars. |
| H1 tags | Number and text of H1 headings. Should be exactly one. |
| Heading structure | Distribution of H1–H6 headings on the page (e.g. {h1: 1, h2: 5, h3: 3}). |
| Total images | Number of <img> elements found on the page. |
| Images without alt | Number of images missing an alt attribute. |
| Word count | Approximate number of words in the visible body text. |
| Paragraph count | Number of text paragraphs detected. |
| DOM node count | Total number of DOM nodes in the page HTML. |
| Top keywords | Most frequent words and their density percentage. |
Related Topics
Content Quality analyses how readable, well-structured, and up-to-date the page'…
Structured data uses standardised formats (JSON-LD, Microdata) to describe page …
Technical SEO covers the infrastructure checks that allow search engines to find…
Run a free SEO audit to see how your site performs in this category.