On-Page SEO: A Practical Checklist for Optimising Every Page You Publish

Key Takeaways

• On-page SEO is a repeatable, systematic process — not a vague art form. Once you have a checklist, every page you publish will be consistently optimised without relying on memory, instinct, or conflicting advice from whichever SEO blog you read last week.
• Keyword density is a defunct concept. No search engine has used raw keyword frequency as a quality signal for over a decade. Modern on-page SEO is about semantic relevance, search intent alignment, and content comprehensiveness — not hitting a 1.5% keyword ratio.
• Search intent is the prerequisite for all other on-page optimisation. If your content format and angle do not match what Google is already ranking for a query, no amount of technical optimisation will compensate for the intent mismatch.
• Your primary keyword belongs in five specific places: the first 100 words, the H1, the page title tag, the URL slug, and the meta description. Beyond those placements, write naturally and use semantic variants rather than repeating the exact phrase.
• Every page on your site should have exactly one H1 tag. Not zero, not two — one. Everything else in your heading hierarchy flows from that single root.
• Image alt text is an accessibility requirement first and an SEO signal second. Write it to describe the image to a visually impaired user; Google’s interpretation of the image will follow from an accurate description.
• Internal linking is the most underused on-page SEO lever available. Every new page you publish is an opportunity to pass authority from your existing high-performing pages — but only if you actively link to the new page from relevant established content.
• The user experience signals that Google uses to evaluate page quality — engagement time, scroll depth, return visit rate — are all downstream consequences of writing clearly, structuring content for scanning, and answering the reader’s question quickly. Readable, useful content is technically optimised content.

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The Evolution of On-Page SEO: Moving Beyond Keyword Stuffing

On-page SEO is the practice of structuring, formatting, and labelling the content on an individual web page so that both search engines and human readers can immediately understand what it is about, who it is for, and why it is the most useful result for a specific query. It is the dimension of SEO that is entirely within your control — unlike backlinks (which depend on others) or domain authority (which accumulates over time), on-page SEO can be executed completely and correctly the moment you press Publish.

What is On-Page SEO vs. Off-Page SEO?

On-page SEO refers to every optimisation you make to the page itself — content, headings, title tags, URLs, internal links, image attributes, and structural formatting. Off-page SEO refers to signals that exist outside your page and largely outside your direct control — backlinks from other websites, brand mentions, social signals, and the authority signals that accumulate across your domain over time.

The two categories interact: a perfectly optimised on-page piece with no backlinks will struggle to rank for competitive queries. A backlink-rich page with poor on-page optimisation will rank below its potential. For most small and medium-sized websites, the practical priority is this: on-page SEO is the foundation that must be correct before off-page efforts can deliver their full return. Backlinks to a poorly structured, intent-misaligned page are partially wasted.

The Myth of “Keyword Density” (Why Readability and Semantics Matter More)

Keyword density — the practice of calculating what percentage of your total word count is occupied by your target keyword and targeting a specific ratio, typically 1–2% — was a legitimate SEO tactic in approximately 2005. Google’s algorithms at that time evaluated relevance primarily through keyword frequency, and writers who repeated their target phrase regularly were rewarded with rankings.

Google’s transition to semantic search, beginning with the Hummingbird update in 2013 and maturing through BERT in 2019 and the MUM model thereafter, fundamentally changed the relevance evaluation framework. Google now understands language at a conceptual level — it can identify a page about boiler installation without counting how many times the phrase “boiler installation” appears, because it evaluates the full semantic context of the content: the related terms used, the questions addressed, the entities mentioned, and the depth of coverage across the topic.

The practical consequence: Writing your target keyword 47 times into a 1,500-word article is not just useless — it actively damages readability, which produces worse engagement signals, which indirectly harms rankings. Write naturally, use your target keyword where it reads genuinely, and complement it with the related terms and semantic variants that a genuinely comprehensive article on the topic would naturally include.

Aligning with Search Intent: The Prerequisite for Any On-Page Optimisation

Search intent is the underlying purpose behind a search query — what the user actually wants to find, learn, or do when they type those words into Google. It is the most important single variable in on-page SEO, and it must be established before any other optimisation step.

Google categorises search intent into four primary types:

• Informational: The user wants to learn something. “How to bleed a radiator”, “what is search intent”, “symptoms of a gas leak”
• Navigational: The user wants to find a specific website. “Google Search Console login”, “Ahrefs pricing page”
• Commercial investigation: The user is evaluating options before a purchase decision. “best boiler brands UK”, “Yoast vs RankMath comparison”
• Transactional: The user is ready to take action. “book plumber Bournemouth”, “buy Nest thermostat”

Why intent matching is the prerequisite: If your page is a blog post but Google is ranking product pages for your target keyword, you have an intent mismatch. A brilliantly optimised informational article will not outrank transactional category pages for a transactional keyword — because Google’s algorithm has determined that users searching that query want to buy, not read.

The intent audit: Before writing or optimising any page, search your target keyword in incognito and study the top five results. What content type dominates — blog posts, product pages, service pages, comparison articles, or video results? What angle or format do the top results share? Your page must match this template or deliberately subvert it with a superior alternative that better serves the same underlying intent.

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Phase 1: The Core Content and Keyword Placement

With intent established, Phase 1 addresses how your target keyword and its semantic companions are placed within the body of your content. The goal is not frequency but strategic placement — ensuring the keyword appears in the specific locations where search engines assign the most relevance weight, while the rest of the content reads naturally and comprehensively.

The First 100 Words: Hooking the Reader and Establishing Relevance

Your target keyword should appear naturally within the first 100 words of your body content — ideally within the first paragraph. This placement serves two purposes: it signals topical relevance to Google’s crawlers, which evaluate opening content heavily when establishing what a page is about, and it confirms to the human reader that they have landed on a page that addresses their query.

The “first 100 words” rule is not about forcing an awkward keyword appearance. It is about the natural structure of well-written content: a strong opening paragraph that establishes the topic, addresses the reader’s implied question, and sets up the value the rest of the article will deliver. A page about boiler installation costs that begins with three sentences about the history of central heating is wasting prime relevance real estate.

The opening paragraph should accomplish three things simultaneously:

1. Confirm the topic (establishing relevance for crawlers)
2. Address the reader’s primary question or pain point (establishing engagement for users)
3. Signal the article’s unique value or angle (establishing a reason to continue reading rather than bouncing back to the search results)

Using LSI and Secondary Keywords Naturally

Latent Semantic Indexing (LSI) keywords are the related terms, synonyms, and contextually associated phrases that a genuinely comprehensive article on your topic would naturally include — not as an optimisation tactic, but because no expert writing about a subject can avoid them.

An article about “on-page SEO checklist” that never mentions title tags, meta descriptions, header tags, internal linking, or search intent would be considered topically incomplete by any human reader. It would also be evaluated as lower quality by Google’s semantic analysis systems, which expect topic-specific vocabulary patterns that indicate genuine domain expertise.

The practical method for identifying semantic keywords:

• Search your primary keyword and note the People Also Ask questions and Related Searches at the bottom of the results — these are the associated topics Google expects a comprehensive resource to cover
• Review the subheadings (H2s and H3s) of the top-ranking pages for your query — they reveal the semantic sub-topics that authoritative content in your space includes
• Use AnswerThePublic or a free Semrush or Ahrefs trial to generate a semantic keyword map around your primary term

Do not create a separate paragraph for each semantic keyword — weave them naturally into the article as the context demands. If the article is genuinely comprehensive, most relevant semantic terms will appear organically without deliberate placement.

Answering the “People Also Ask” Questions Within Your Content

Google’s “People Also Ask” (PAA) boxes are a direct signal from the algorithm about which sub-questions it associates with your primary query — and an article that addresses those sub-questions comprehensively is providing exactly the semantic coverage Google expects from a high-quality result on that topic.

Beyond the ranking benefit, PAA questions represent a genuine opportunity to appear in a featured snippet position for related queries without those queries being your primary target. A well-structured answer to a PAA question — approximately 40–60 words, immediately following a subheading that mirrors the question — is formatted exactly for Google’s featured snippet extraction system.

Practical implementation: Search your primary keyword, expand the PAA box, and identify the two or three most relevant questions. Create an H2 or H3 for each one (phrasing it as the question or a close variant) and answer it concisely but completely in the paragraph immediately beneath the heading. This doubles as both semantic optimisation and featured snippet targeting — with no additional content investment beyond answering questions that a comprehensive article on the topic should address anyway.

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Phase 2: Structuring Your Page with Header Tags (H1, H2, H3)

Header tags — H1 through H6 — are HTML elements that create a visible and machine-readable hierarchy of your page’s content. They tell both users (who scan headings to navigate long articles) and search engines (which use heading hierarchy to understand a page’s structure and subtopic coverage) what the page contains and how its content is organised. A page with no headings, or with headings used randomly for styling rather than structure, is significantly harder for both audiences to evaluate.

The Golden Rule of the H1 Tag (One Per Page, Compelling, and Keyword-Focused)

Every page on your website should have exactly one H1 tag. This is not a stylistic recommendation — it is a technical and semantic standard. The H1 is the single most important on-page relevance signal, communicating to Google in explicit terms what the page is primarily about. Multiple H1 tags create ambiguity about the page’s primary topic. Zero H1 tags remove the strongest relevance signal available.

What makes a strong H1:

• Includes the primary keyword — naturally, not forced. “On-Page SEO Checklist: How to Optimise Every Page You Publish” is better than both “A Checklist” (no keyword) and “On-Page SEO Checklist: On-Page SEO Tips for On-Page SEO” (stuffed)
• Is compelling to a human reader — the H1 is the first thing a user sees after the title in the SERP. It should confirm they have arrived at the right page and give them a reason to continue reading
• Is not identical to your title tag — the H1 and the title tag can contain the same keyword but should be phrased differently. Identical H1 and title is a missed opportunity to use two slightly different angles on the same topic
• Appears only once, at the top of the page — not repeated in the body content as a section header

In WordPress: Your post or page title (the field at the very top of the editor) automatically becomes your H1 in most well-coded themes. Do not add a second H1 in the body content using the H1 formatting option in your editor.

Using H2s to Break Up Main Concepts and Target Long-Tail Queries

H2 headings are the primary structural layer of your content — they define the main sections of your article and communicate to Google the range of subtopics the page covers. Well-crafted H2s serve three functions simultaneously: they guide human readers who scan before reading, they signal topical breadth to Google’s semantic analysis, and they can individually target long-tail query variations related to your primary keyword.

H2 best practices:

• Each H2 should represent a distinct conceptual section — not just a formatting break in continuous prose
• H2s should be descriptive and specific, not vague. “Phase 2: Structuring Your Page with Header Tags” communicates content. “More Tips” does not
• Where natural, include secondary keywords or semantic variants in H2 wording — a user searching “how to use H2 tags for SEO” who lands on an article with that exact phrase as an H2 heading has found a relevant, intent-matched page
• Space your H2s appropriately — a 2,000-word article with only one H2 is not well-structured; the same article with 15 H2s has been over-fragmented into unusable chunks

Why You Should Never “Skip” Heading Levels for Styling Purposes

The heading hierarchy (H1 → H2 → H3 → H4) must be used in sequential order — an H3 should only appear as a subheading within an H2 section, not as a standalone heading where an H2 would be structurally appropriate. Skipping from an H2 directly to an H4, or using an H4 as the first subheading beneath an H1, breaks the semantic hierarchy that both screen readers (an accessibility concern) and search engine crawlers use to map the page’s content structure.

The practical test: Read your heading structure in isolation — just the headings, stripped of all body text. Does the sequence of headings tell a coherent, nested story about your content? If the heading hierarchy makes sense as an outline, it is correctly structured. If it requires the body content to clarify the relationship between headings, the hierarchy has a structural problem.

The common mistake: Using H3 or H4 tags because they render at a visually preferred size in a theme, rather than because they represent the correct structural level for that content. Heading levels communicate semantic hierarchy — use CSS or your page builder’s styling options to adjust visual presentation separately from the semantic heading level.

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Phase 3: The “Behind the Scenes” HTML Elements

The title tag, meta description, and URL slug are the three elements that determine how your page appears in Google’s search results — they are the first impression your content makes on a prospective visitor before they click. Optimising them is not about impressing Google’s algorithm; it is about maximising the proportion of people who see your result and choose to click it.

Crafting Click-Worthy Title Tags (Keeping It Under 60 Characters)

The title tag is the clickable blue headline that appears in Google’s search results pages. It is separate from your H1 (though often similar in content), and it is the single most important click-through rate determinant in organic search — a compelling title tag on a page ranking at position four will generate more clicks than a bland title on a page ranking at position two.

Title tag specifications:

• Length: Keep under 60 characters (approximately 580 pixels of display width in Google’s desktop SERP). Titles longer than this are truncated mid-sentence, which reduces click appeal and occasionally produces embarrassing truncations. Use a free title tag preview tool (e.g. SERP Simulator at mangools.com/serp-simulator) to verify your title renders in full.
• Primary keyword placement: Include your primary keyword as close to the beginning of the title as naturally reads. Google bolds the keyword in search results when it matches the user’s query — front-loaded keywords are more visually prominent.
• Compelling modifier: A title that includes a specific modifier — “Complete Guide”, “Checklist”, “2025”, “Step-by-Step”, “Free”, “UK” — typically generates higher CTR than a bare keyword title because it signals specific value or currency to the searcher.
• Brand appendage: For small businesses, including your brand name at the end of the title tag (“| [Brand Name]”) builds brand recognition in search results over time — but omit it if it pushes your title over the 60-character limit.

Title tag formula for a content page: [Primary Keyword]: [Compelling Value Modifier] — [Brand Name]
Example: “On-Page SEO Checklist: 30 Steps for Every Page You Publish — [Brand]”

Writing Meta Descriptions That Drive CTR

The meta description is the 150–160 character snippet of text that appears below your title tag in search results. It is not a direct ranking factor — Google confirmed years ago that meta description content does not influence where your page ranks. What it does influence significantly is click-through rate, which is the proportion of people who see your result and choose to click it.

Meta description best practices:

• Length: 150–160 characters. Longer descriptions are truncated; shorter ones sometimes get auto-expanded by Google with text pulled from the page body (which is rarely as well-crafted as a deliberate description).
• Include the primary keyword: Not for ranking purposes, but because Google bolds matching search terms in the meta description — making your result more visually prominent to the searcher.
• End with a specific CTA: “Start optimising your pages today”, “Download the free checklist”, “Get a free quote” — a specific action is more compelling than a summary that stops without direction.
• Write for the reader, not the algorithm: The meta description is marketing copy for your page. It should explain what the reader will gain from clicking and address the specific need that drove their search. “Learn the exact on-page SEO steps professional content teams use before every publish — including a printable checklist” is more persuasive than “This article covers on-page SEO. It includes tips and advice.”

When Google ignores your meta description: Google rewrites meta descriptions for approximately 70% of queries, pulling text directly from the page that it considers more relevant to the specific search query. This is not a failure on your part — it is Google dynamically matching the snippet to the user’s precise wording. The best prevention is having genuinely comprehensive page content and a well-structured page, so that whatever text Google selects reads coherently as a description.

Optimising the URL Slug (Keep It Short, Clean, and Keyword-Rich)

The URL slug is the portion of your page URL that follows your domain name — the /on-page-seo-checklist/ in yoursite.co.uk/on-page-seo-checklist/. It appears in the green breadcrumb text in search results, in browser address bars, and in any links others share to your content — making it a minor relevance signal for Google and a trust signal for human readers.

URL slug best practices:

• Include the primary keyword: yoursite.co.uk/on-page-seo-checklist/ is preferable to yoursite.co.uk/p=4271 or yoursite.co.uk/blog/posts/2025/march/article-about-seo/
• Remove stop words: Remove articles, prepositions, and conjunctions that add length without adding meaning. /on-page-seo-checklist/ not /the-ultimate-on-page-seo-checklist-for-all-pages/
• Use hyphens, not underscores: Google treats hyphens as word separators (making on-page-seo three distinct words); underscores are not treated as separators (making on_page_seo a single unrecognised string)
• Keep it lowercase: URL strings are case-sensitive in some server configurations; lowercase prevents duplicate URL issues
• Do not change URLs on published pages without implementing a 301 redirect. An existing URL that has accumulated backlinks and search traffic is an asset. Changing it without a redirect destroys that asset completely.

In WordPress: The URL slug is editable in the post editor under the title field (classic editor) or in the right sidebar under the Permalink panel (Gutenberg). Set it before publishing — changing it after is possible but requires a redirect.

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Phase 4: Image SEO and Multimedia Optimisation

Images are simultaneously an opportunity and a liability in on-page SEO. Properly optimised images contribute relevance signals, accessibility compliance, and a richer user experience. Unoptimised images are among the most common sources of slow page load times — and as established in the technical SEO guide, a page that loads slowly on mobile creates user experience failures that negatively affect rankings.

Descriptive File Naming (Why “IMG_9948.jpg” Hurts Your SEO)

Before an image is uploaded to your CMS, rename the file to include a descriptive, keyword-relevant name. Google cannot see your images the way a human can — it reads the file name, alt text, surrounding content, and page context to understand what an image depicts. A file named IMG_9948.jpg provides zero contextual information. A file named on-page-seo-checklist-diagram.jpg tells Google immediately what the image depicts and reinforces the page’s topical relevance.

File naming rules:

• Use descriptive, specific language: boiler-installation-portsmouth.jpg is better than plumber-job.jpg
• Separate words with hyphens (not underscores or spaces)
• Include the primary keyword where it is genuinely descriptive of the image — not in every image on the page
• Keep names concise — 3–5 words is typically sufficient
• Use lowercase throughout

Writing Accessibility-First Alt Text (Describe the Image, Don’t Stuff Keywords)

Alt text (alternative text) is an HTML attribute applied to every image tag that describes the image content for users who cannot see it — including screen reader users, users on text-only browsers, and users whose browser fails to load the image. It is an accessibility requirement under WCAG (Web Content Accessibility Guidelines) and an SEO signal that helps Google understand image content and page relevance.

The correct approach to alt text:
Write alt text as if describing the image to someone over the phone who cannot see it. “Illustrated checklist showing the six phases of on-page SEO optimisation, with checkboxes for each step” is correct. “On-page SEO checklist on-page SEO tips SEO optimisation best practices” is keyword stuffing that fails both accessibility and quality standards.

Alt text guidelines by image type:

Image Type	Alt Text Approach	Example
Informational image	Describe fully — what is shown and why it matters	“Bar chart showing organic traffic increase of 340% over 8 months after implementing topic cluster strategy”
Decorative image	Leave alt text empty (alt=””) — screen readers skip it	Hero background image with no informational content
Functional image (button/icon)	Describe the function, not the appearance	“Download on-page SEO checklist PDF”
Product image	Include product name, variant, and key visible features	“Nest Learning Thermostat in white, installed on cream wall”
Person/team photo	Name the individual and their role	“Jane Davies, Senior SEO Strategist at [Company Name]”

Maximum length: Most SEO guidance recommends keeping alt text under 125 characters — this is the point at which most screen readers truncate the description.

Compressing Images for Faster Page Load Speeds (WebP Format)

Every uncompressed image on your page adds unnecessary load time that degrades user experience and can suppress rankings. A photograph downloaded directly from a camera or stock library is typically 3–8MB — ten to twenty times larger than the web-optimised equivalent. A page with six such images is adding 20–50MB of download weight before a single word of content loads.

The practical compression workflow:

• Resize before uploading: Use Squoosh (squoosh.app, free, browser-based) to resize images to a maximum width of 1,200–1,400 pixels and convert to WebP format before uploading to your CMS. A 4,000px-wide photograph resized to 1,200px loses nothing visible at web display sizes but gains dramatic file size reduction.
• Enable automatic compression in WordPress: Install ShortPixel or Imagify (both have free tiers sufficient for most small sites) to automatically compress and convert images to WebP on upload, and to retroactively optimise your existing media library.
• Use WebP format where possible: WebP is Google’s open image format that delivers equivalent visual quality to JPEG at approximately 25–35% smaller file sizes. All major browsers support WebP. Most modern WordPress image compression plugins convert to WebP automatically.
• Set explicit width and height attributes: Adding width and height HTML attributes to image tags allows the browser to pre-allocate space for the image during page load, eliminating Cumulative Layout Shift (the visual jumping that occurs when images load and push content down). Most modern page builders and CMS platforms set these attributes automatically.

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Phase 5: The Linking Ecosystem

The links on and to your page — internal links to and from your own site, and outbound links to external sources — are a critical component of on-page SEO that is frequently deprioritised by content writers focused on body copy. Both link types serve distinct purposes: internal links distribute authority and signal content relationships; outbound links build credibility through association with authoritative external sources.

Internal Linking: Passing Link Equity from High-Authority Pages to Your New Post

Every new page you publish starts with zero accumulated authority. It has not been linked to by any external sites, it has not been shared, and it has not been evaluated by Google’s quality systems over time. The fastest way to give a new page an authority boost is to link to it from pages on your own site that have already accumulated authority — established pages with existing backlinks, strong rankings, and good engagement metrics.

The internal linking workflow for every new page:

• After publishing your new page, identify three to five existing pages on your site that are topically related to the new content
• Edit each of those existing pages to add a contextual internal link to your new page, using descriptive anchor text that naturally introduces the link
• Verify that the new page itself contains two to four internal links pointing to other relevant pages on your site (distributing authority outward as well as receiving it)
• Ensure the new page is linked from your relevant topic cluster’s pillar page, if one exists

The priority internal links to add to every new page:

• A link from your highest-authority existing page on a related topic (check your GSC Performance report to identify which of your pages currently receives the most organic clicks — these carry the most authority to pass)
• A link from any pillar or hub page that covers the broader topic area your new content supports
• A link from any recent high-performing content on a related subject (recent content is frequently visited and passes its engagement momentum to the pages it links to)

Choosing Strategic Anchor Text for Internal Links

Anchor text is the visible, clickable text of a hyperlink. For internal links, anchor text is a relevance signal: it tells both Google and users what the linked page is about. “Read our complete guide to on-page SEO” communicates more relevance information than “click here” — and the keyword-descriptive anchor text reinforces the topical relationship between the linking page and the linked page.

Internal anchor text best practices:

• Use descriptive, keyword-relevant anchor text that accurately describes the destination page’s content — “on-page SEO checklist”, “local SEO strategy for tradesmen”, “boiler installation costs Portsmouth”
• Vary anchor text across different links to the same page — repeated identical anchor text from multiple pages is an unnatural pattern; varied natural phrasing reads organically
• Avoid generic anchors: “click here”, “read more”, “this article”, “here” provide no topical signal to crawlers and no content preview to users
• Do not over-optimise: internal anchor text should read naturally within its surrounding sentence — a reader should be able to understand why the link exists from context, without the anchor feeling forced

The Value of Outbound Linking (Citing Authoritative Sources to Build Trust)

Linking out to high-quality, authoritative external sources is a trust signal, not a traffic leak. As established in the authority and trust-building guide, hoarding link equity by refusing to cite external sources signals to both readers and Google that your content cannot withstand scrutiny. Well-cited content reads as more credible — to both human readers and to Google’s Quality Rater evaluators — than identical content that makes the same claims without any external attribution.

The outbound linking standard for content pages:

• Every specific factual claim, statistic, research finding, or third-party observation that is not common knowledge should have a link to the source
• Links should point to Tier 1–5 sources from the evidence hierarchy covered in the trust-building guide — peer-reviewed studies, government data, institutional reports, established journalism
• Open external links in a new tab (target="_blank") to prevent users from losing their place on your page
• Do not link to competitors’ commercial pages — link to authoritative informational or data sources rather than to commercial alternatives to your own product or service

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Phase 6: Readability and User Experience (UX) Signals

The final phase of on-page SEO addresses the factors that determine whether a user who arrives on your page stays long enough to engage with your content — or immediately bounces back to the search results. Bounce rate, dwell time, and return visit rates are all behavioural signals that Google uses as indirect quality indicators. A page with excellent keyword placement and a perfect title tag that drives 90% bounce rate is not a high-quality result by any meaningful measure.

Avoiding “Walls of Text” (Short Paragraphs, Bullet Points, and Bold Text)

Web readers do not read — they scan. F-pattern and Z-pattern eye-tracking research (covered in the conversion psychology guide) demonstrates that users navigate content by scanning headings and the first sentence of each paragraph, spending minimal time on mid-paragraph text. Content formatted with this scanning behaviour in mind achieves significantly higher engagement than content formatted for linear reading.

The formatting principles that aid online scanning:

• Paragraph length: Maximum three to four sentences per paragraph for body content, ideally two to three. A five-line paragraph on a mobile screen is a wall of text. A one-to-two sentence paragraph is immediately digestible.
• Bullet points and numbered lists: Use for any content that is genuinely list-like — steps in a process, items in a category, characteristics of something. Do not convert flowing argumentative prose into bullet points — lists work for enumerable items, not for complex reasoning.
• Bold text for key phrases: Bold (not italic, not underline) draws the scanning eye to the most important concept in a paragraph. Use it for one to two key terms or phrases per section — not for emphasis on generic words, and not so frequently that every other sentence is bolded.
• Sub-headings every 250–350 words: Regular heading breaks reset the scanner’s attention and provide navigational signposts that allow users to jump to the section most relevant to their specific need.

Expert Tip: Write your first draft without any formatting constraints, then apply formatting in a dedicated edit pass. Attempting to format while drafting interrupts the creative writing flow and often produces over-formatted content where bullet points break up reasoning that would read better as connected prose.

Above the Fold Optimisation: Getting Straight to the Answer

“Above the fold” refers to the content a user sees on first page load without scrolling — the portion of your page visible before any scroll action is required. On mobile, this is a small area — typically the headline, the first paragraph, and perhaps a featured image. Every pixel of above-the-fold space is prime real estate that either confirms to the user they have found the right page, or gives them a reason to leave.

The above-the-fold audit:
Load your published page on a real mobile device (not a desktop browser’s mobile view simulation — an actual phone) and ask: without scrolling, does this page make it immediately clear what topic it covers and what value it will provide to the reader? If the answer is no — if the hero section is dominated by a large image with no text, or if the first paragraph is a generic contextual preamble that does not address the reader’s specific need — the above-the-fold experience needs restructuring.

Common above-the-fold failures:

• A large hero banner image that pushes all text below the fold on mobile
• An opening paragraph that provides general context rather than directly addressing the query
• A prominent cookie consent banner that covers the content (an increasing legal requirement, but its visual impact on first impression should be minimised)
• A full-screen newsletter pop-up triggered on page load before the user has read anything (an intrusive interstitial that Google’s algorithm specifically deprioritises)

Ensuring Mobile Responsiveness Before Hitting Publish

Google uses the mobile version of your page as its primary quality evaluation basis. Before publishing any new page, load it on a physical mobile device and complete a genuine usability test: can you read the content without zooming? Can you tap the navigation links and CTA buttons without accidentally hitting adjacent elements? Does the page load within three to five seconds on a standard mobile data connection?

The pre-publish mobile checklist:

• [ ] Text is readable at default size without zooming
• [ ] All buttons and links are tappable without accidentally hitting adjacent elements
• [ ] No content extends beyond the screen width (no horizontal scrolling)
• [ ] Images display correctly and do not overflow the viewport
• [ ] The contact form or primary CTA is visible and functional without errors
• [ ] Page loads within 5 seconds on a 4G connection (test with Google’s Mobile-Friendly Test tool)
• [ ] No intrusive pop-ups trigger immediately on page load

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Your Quick-Fire Pre-Publish Checklist

Print this, paste it into your project management tool (Notion, Trello, Asana, or a simple Google Doc), and work through it for every page you publish. A complete pre-publish checklist completed consistently is worth more than a sophisticated technical audit conducted irregularly.

✅ Search Intent and Research

• [ ] Searched the target keyword in incognito and confirmed the top results match my planned content type and angle
• [ ] Identified three to five secondary and semantic keywords to include naturally
• [ ] Noted the top two to three PAA questions to address within the content

✅ Core Content and Keyword Placement

• [ ] Primary keyword appears naturally within the first 100 words
• [ ] Primary keyword appears in the H1 tag
• [ ] Secondary and semantic keywords are woven naturally throughout the body
• [ ] PAA questions are addressed within the content using H2 or H3 headings
• [ ] No keyword stuffing — the primary keyword phrase is used naturally, not repeatedly forced

✅ Heading Structure

• [ ] Exactly one H1 tag on the page
• [ ] H1 includes the primary keyword and is compelling to a human reader
• [ ] H2s divide the main conceptual sections logically
• [ ] H3s appear only within H2 sections (no skipped heading levels)
• [ ] Heading structure reads as a coherent content outline in isolation

✅ Title Tag and Meta Description

• [ ] Title tag is under 60 characters and includes the primary keyword near the front
• [ ] Title tag is compelling and includes a value modifier or year if appropriate
• [ ] Meta description is 150–160 characters
• [ ] Meta description includes the primary keyword and ends with a specific CTA
• [ ] Title tag and H1 are different phrasings (not identical)

✅ URL Slug

• [ ] URL slug is short and includes the primary keyword
• [ ] Stop words (the, a, and, of, for) have been removed
• [ ] Slug uses hyphens, not underscores or spaces
• [ ] URL is all lowercase
• [ ] Slug has been set before publishing (not left as WordPress auto-generated with full title)

✅ Images and Media

• [ ] All image files have been renamed descriptively before upload
• [ ] All informational images have descriptive alt text (under 125 characters)
• [ ] Decorative images have empty alt text (alt=””)
• [ ] All images have been compressed and converted to WebP format
• [ ] No image is wider than 1,200–1,400 pixels at upload
• [ ] Featured image is set and displays correctly on mobile

✅ Internal Linking

• [ ] The new page contains two to four internal links to relevant existing pages
• [ ] At least two to three existing pages have been updated to link to this new page
• [ ] All internal anchor text is descriptive and keyword-relevant
• [ ] The page is linked from any relevant pillar or hub page

✅ Outbound Linking

• [ ] All specific statistics, research findings, and third-party claims include a link to their source
• [ ] All external links open in a new tab
• [ ] Linked sources are high-quality (Tier 1–5 on the evidence hierarchy — academic, government, institutional, established journalism)

✅ Readability and UX

• [ ] Paragraphs are a maximum of three to four sentences
• [ ] List items are used for genuinely list-like content (not to fragment prose)
• [ ] One to two key phrases per section are bolded
• [ ] A subheading appears at least every 250–350 words
• [ ] The opening above-the-fold section addresses the reader’s query without requiring a scroll
• [ ] Page has been loaded on a real mobile device and passed a visual usability check
• [ ] No full-screen pop-up triggers immediately on page load

✅ Final Technical Checks

• [ ] Page is set to “Public” and not accidentally set to draft, private, or noindex
• [ ] Canonical tag points to this page’s own URL (self-referential canonical — managed by RankMath or Yoast automatically)
• [ ] Open Graph image is set (the image that appears when the URL is shared on social media)
• [ ] After publishing, URL has been submitted for indexing via Google Search Console URL Inspection tool

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Conclusion

Every experienced SEO professional has a version of this checklist — some version of the systematic pre-publish process that ensures nothing important falls through the cracks between writing and publishing. The difference between a content team that consistently produces well-optimised pages and one that produces inconsistent results is rarely knowledge — it is the presence or absence of a repeatable process.

The checklist above is not the final word on on-page SEO. It will evolve as Google’s algorithm evolves, as new ranking factors emerge, and as your specific competitive context shifts. But as a starting-point SOP for any content creator managing their own pages, it covers every element that genuinely matters for search visibility and user experience — and deliberately omits everything that does not.

Copy it, customise it for your specific CMS and workflow, paste it into your task management tool of choice, and run through it every single time you hit Publish. The consistency of application is what builds the compounding advantage — not the sophistication of any individual optimisation.

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FAQ

Does on-page SEO matter for short-form pages like contact pages and service pages, or just for long blog posts?

On-page SEO applies to every indexable page on your site, not just long-form content. For short pages like contact pages, you will be applying a subset of the checklist (title tag, meta description, URL, alt text, mobile check) rather than the full content optimisation workflow — there is no body text to optimise for keyword placement or header hierarchy on a five-line contact form page. Service pages, however, merit full on-page optimisation treatment: they are the pages most directly connected to commercial intent queries and the most likely to drive enquiries and conversions. A service page for “boiler installation Dorchester” benefits from every element of this checklist.

How long should my content be to rank on page one?

There is no universally correct answer, and anyone who tells you that all articles need to be 2,000+ words is applying a generalisation that ignores search intent. The correct content length is whatever length is required to comprehensively and clearly answer the query better than the pages currently ranking. Search your target keyword in incognito and estimate the average length of the top three results — this is your baseline. If the top results are 1,200-word articles, a 4,000-word version of the same content is not inherently better; it may be worse if the additional length is padding rather than substance. For definitional queries (“what is a canonical tag”), 500 well-chosen words may suffice. For procedural queries (“how to set up Google Search Console”), 2,500 words of step-by-step instruction may be the minimum required to fully serve the user.

My current pages are not optimised. Should I focus on optimising existing content or publishing new content?

Both, but the prioritisation depends on your situation. Optimising existing pages is typically faster and produces results more quickly than creating new content — the page is already indexed, Google has already formed an opinion about its relevance, and targeted improvements to title tags, meta descriptions, and content depth can produce measurable ranking improvements within weeks. Creating new content is the mechanism for expanding your site’s topical footprint into new query areas. The most efficient approach: identify your highest-traffic existing pages in Google Search Console and apply the on-page checklist to each of them first. Simultaneously, identify the most commercially valuable gaps in your content coverage and begin building the new pages that fill them. Both activities compound over time; neither should be deferred while the other is completed.

How often should I update on-page optimisation for published pages?

Revisit your most commercially important pages at least twice per year to check: Are the title tag and meta description still optimal given how competition has shifted? Does the content accurately reflect current information, pricing, or guidance? Are there new PAA questions associated with the topic that the page does not currently address? Has the search intent for the primary keyword shifted in a way that requires a content or format change? For evergreen instructional content, a thorough annual review with minor ongoing updates as facts change is sufficient. For pricing pages, regulatory content, or anything time-sensitive, review quarterly or whenever the underlying information changes.

I’ve used RankMath and it gives my post a 100/100 score. Does that mean it’s fully optimised?

RankMath’s score is a useful checklist verification tool, but it measures a specific set of technical and on-page signals that are configured into its scoring system — not the holistic quality of your page as a search result. A page can score 100/100 in RankMath and still fail to rank because: the content does not genuinely address search intent, the writing is thin or generic despite technical optimisation, the page has no internal links from authoritative pages on the site, or the competitive landscape requires more content depth than RankMath’s checklist evaluates. Use the RankMath score as a confirmation that your technical on-page elements are present and correctly configured — then layer the content quality, semantic depth, and trust signals from this guide on top of it.