On-page SEO covers everything on your actual web pages that influences how Google understands and ranks them. Unlike backlinks — which depend on other people — on-page SEO is entirely in your control. Fix these ten things first, and you give Google exactly what it needs to rank your pages.
This list is ordered by impact, not alphabetically. Start at the top.
1. One Target Keyword Per Page
Every page should be optimised for a single primary keyword (or closely related phrase). Trying to rank one page for five different keywords dilutes your focus and confuses Google about what the page is actually about. Decide what one query you want each page to rank for, and build the entire page around answering that query better than any competitor.
Check: Can you state in one sentence exactly what search query each of your key pages is targeting?
2. Title Tag: 50–60 Characters, Keyword Near the Start
The title tag is the single most important on-page SEO element. It appears as the blue link in Google search results and tells both Google and searchers what the page is about. Include your target keyword as close to the beginning as naturally possible. Keep it under 60 characters or Google will truncate it. Write it for a human first — a good title tag gets clicks, and click-through rate is a ranking signal.
Check: Are all your key pages' title tags unique, under 60 characters, and do they include the target keyword?
3. Meta Description: 150–160 Characters, Includes a CTA
Meta descriptions don't directly affect rankings, but they heavily influence whether someone clicks your result. A compelling meta description — one that tells the searcher exactly what they'll get and why your page is the best answer — improves your click-through rate, which does influence rankings indirectly. Include your keyword (Google bolds it in results when it matches the search query), and end with a soft call to action.
Check: Does every important page have a unique, compelling meta description under 160 characters?
4. H1 Tag: One Per Page, Contains the Target Keyword
The H1 tag is your page's main heading — the one that appears at the top of the page content. There should be exactly one H1 per page (not zero, not three). It should contain your target keyword, ideally close to the start. Your H1 doesn't have to be identical to your title tag — in fact, slight variation can be useful — but they should both make it obvious what the page is about.
Check: Does every page have exactly one H1 that includes the target keyword?
5. URL Structure: Short, Descriptive, Keyword-Inclusive
Your URL is a ranking signal and a user experience factor. A URL like /on-page-seo-checklist is better than /blog/post?id=447&cat=seo&ref=home in every way — Google can read it, users trust it, and it includes the keyword. Keep URLs short (ideally under 60 characters), use hyphens between words (not underscores), remove stop words like "a", "the", "and", and include your primary keyword.
Check: Are your URLs clean, short, and do they include the target keyword?
6. Content Length and Depth: Match (or Beat) the Top Results
There's no magic word count for SEO. The right length is whatever fully answers the search query. A good rule of thumb: search your target keyword and look at the top three results. If they average 1,200 words, a 300-word page won't outrank them. Your content needs to cover the topic at least as thoroughly. Use subheadings (H2s and H3s) to structure longer content, naturally include related terms and synonyms, and answer the specific questions a searcher would have.
Check: Does your page content genuinely and completely answer the search query it targets?
7. Keyword in the First 100 Words
Google gives more weight to text that appears early in the page content. Get your target keyword into the first paragraph — naturally, not forced. This confirms to Google immediately what the page is about. Don't start with a preamble; get to the point in the first sentence and work your keyword in within the first 100 words.
Check: Does your target keyword appear naturally in the opening paragraph of each key page?
8. Image Alt Text: Descriptive, Includes Keywords Where Natural
Alt text serves two purposes: it tells visually impaired users and screen readers what an image depicts, and it tells Google what the image is about. Every image on your page should have alt text. For important images, include your target keyword where it fits naturally. Avoid keyword stuffing ("seo audit free seo tool seo checker") — write a genuine description of what the image shows. Images with descriptive alt text can also rank in Google Image Search, driving additional traffic.
Check: Do all images on your key pages have meaningful, descriptive alt text?
9. Internal Links: Connect Related Pages With Descriptive Anchor Text
Internal links — links from one page on your site to another — pass authority around your site and help Google understand the relationship between your pages. Link to related content using descriptive anchor text (the clickable words). "Read our guide to keyword research" is better anchor text than "click here." Every important page on your site should be reachable through at least two internal links, and your highest-priority pages should have the most internal links pointing to them.
Check: Do your key pages link to related content, and do other pages link back to them?
10. Page Speed: Under 3 Seconds on Mobile
Page speed is a confirmed Google ranking factor, and mobile speed matters most — Google uses your mobile site for ranking decisions. Three seconds is the threshold; below it, most users will wait. Above it, you start losing visitors and rankings. The biggest speed wins are almost always: compressing and converting images to WebP format, removing unused JavaScript, and enabling browser caching. Google's PageSpeed Insights (or a full SEO audit) will show you exactly what's slowing your specific pages down.
Check: Does your site load in under three seconds on a mobile connection?
How to Audit All 10 in 30 Seconds
Going through this checklist manually for every page on your site takes hours, and it's easy to miss things. GoogleGain checks all of these factors automatically — plus 90 more — and gives you a prioritised list of exactly what to fix on your specific site, in plain English.
It's free, takes 30 seconds, and requires no account. Paste your URL and get your full on-page SEO report instantly.