What Is On-Page SEO?
On-page SEO (also called on-site SEO) is the practice of optimising individual web pages to rank higher in search engine results and earn more relevant traffic. It involves optimising both the content and the HTML source code of a page, as opposed to off-page SEO which refers to links and other external signals.
On-page SEO is the foundation of any SEO strategy because it is entirely within your control. You do not need to wait for other websites to link to you or for social media to pick up your content. You can make on-page changes right now and see the effects as soon as search engines recrawl your pages.
On-Page SEO vs Off-Page SEO vs Technical SEO
| Type | What It Covers | Control |
|---|---|---|
| On-Page SEO | Content, title tags, meta descriptions, headings, images, internal links, keyword usage | Full control |
| Off-Page SEO | Backlinks, brand mentions, social signals, domain authority | Limited control |
| Technical SEO | Site speed, mobile-friendliness, crawlability, indexing, structured data, HTTPS | Full control |
The Key Elements of On-Page SEO
1. Title Tags
The title tag is the most important on-page SEO element. It appears as the clickable headline in search results and in the browser tab. Best practices:
- Keep between 30-60 characters
- Include your primary keyword near the start
- Make every title unique across your site
- Add your brand name at the end
2. Meta Descriptions
The meta description is the snippet of text below the title in search results. While it does not directly affect rankings, a well-written description significantly increases click-through rate. Aim for 120-160 characters with a clear call to action.
3. Heading Structure
Use heading tags (H1-H6) to create a clear content hierarchy. Every page should have exactly one H1 containing the primary keyword. Use H2s for main sections and H3s for subsections. This helps both users and search engines understand your content structure.
4. Content Quality
Content is the core of on-page SEO. Your content should:
- Thoroughly answer the searcher's question (search intent)
- Be at least 300 words for standard pages, longer for competitive topics
- Use natural language with relevant keywords (check with a keyword density checker)
- Be written at an appropriate readability level for your audience
- Include original insights, data, or perspectives
5. Image Optimisation
Every image should have descriptive alt text, proper width and height attributes, and use lazy loading for images below the fold.
6. Internal Links
Link to related pages within your site using descriptive anchor text. Internal links help search engines discover content and understand the relationship between pages. Use a link analyser to check your internal linking.
7. URL Structure
Keep URLs short, descriptive, lowercase, and hyphenated. Avoid parameters and excessive depth. Check your URL structure with RankNibbler.
On-Page SEO Checklist
For a complete step-by-step guide, see our on-page SEO checklist which covers every element you need to review.
How to Check Your On-Page SEO
The fastest way to check your on-page SEO is to run an audit. Enter your URL on the RankNibbler homepage and get a score out of 100 with specific recommendations for every issue found. You can also use the site audit tool to check every page on your website at once.
Last updated: March 2026