SEO basics
What is on-page SEO?
On-page SEO is the practice of optimising the content and HTML of individual web pages so search engines understand what each page is about and rank it for relevant queries. It covers everything a developer or content writer directly controls: the page's title tag, meta description, heading structure, body copy, keyword usage, internal links, and image attributes. According to Google's Search Central documentation, helping search engines understand your page's content is the foundation of appearing in relevant results. On-page SEO differs from off-page SEO (what other sites say about you) and technical SEO (the infrastructure crawlers need to access the page). Of the three, on-page is where most businesses start — it is fully within your control and produces visible results before any external factors come into play.
Title tags and meta descriptions
The title tag is the blue link text that appears in Google search results. It is the single most important on-page element for telling Google — and the searcher — what a page is about. Each page must have a unique title tag that includes the primary keyword near the front and stays under 60 characters so it displays in full. According to Google's guidance on title links, the title is used as the headline in search results and carries significant weight in determining relevance.
The meta description does not directly influence rankings, but it controls the snippet text below the title in search results — which directly influences whether someone clicks. Write it as a direct pitch: what is on this page and why should the searcher visit. Keep it under 160 characters and make it unique per page.
Heading structure
Every page should have exactly one H1 that matches (or closely mirrors) the page's primary topic and title tag. H2s break the page into logical sections. H3s handle sub-points within those sections. Google uses heading hierarchy to understand the structure and relative importance of content — skipping levels (jumping from H1 to H3) or using multiple H1s confuses that signal. According to Google's Search Central documentation on headings, headings help Google understand the structure of the page. Beyond SEO, a clean heading hierarchy makes pages accessible to screen reader users — a requirement, not an afterthought.
Body content and keyword usage
Content should answer the searcher's actual question, not chase a keyword count. Google's systems are sophisticated enough to recognise synonyms and related concepts — so writing naturally for a human reader produces better results than stuffing an exact phrase into every paragraph. The question to ask of every page is: could a stranger with no background in this topic have written this in ten minutes? If yes, the page is generic and will not earn trust or rankings. If it could only have come from someone with real expertise and first-hand experience, the page is building genuine authority. Moz's guide to on-page factors covers keyword placement, content depth, and topical coverage in detail.
Internal linking
Internal links (links from one page on your site to another) serve two purposes: they help users navigate to related content, and they pass authority signals between pages. A well-linked site distributes ranking signals from high-authority pages (like the homepage) to deeper pages (like service or area pages) that need it. Every page should link to at least one other relevant page, and no page should be an orphan — reachable only by direct URL with no internal links pointing to it. Anchor text (the clickable words in a link) should be descriptive and relevant to the page being linked to, never "click here."
Image optimisation
Every image on a page should have a descriptive alt attribute that explains what the image shows — both for search engines indexing image content and for screen reader users who cannot see the image. Images should have explicit width and height attributes set to prevent layout shift (a Core Web Vitals metric). Use modern image formats (WebP) and lazy-load all images except the first visible image on the page (the LCP image), which should load immediately. Unoptimised images are one of the most common causes of poor page speed scores, and page speed is a confirmed Google ranking input.