SEO Tools Explained: What Each Type Does and When to Use It
What are SEO tools?
SEO tools are software that help you measure, diagnose and improve a website's performance in search. They fall into a few groups: Google's own tools such as Search Console, GA4 and PageSpeed Insights; site crawlers such as Screaming Frog; and research suites such as Ahrefs and Semrush. Google's tools report real data about your site, while third-party tools mostly provide estimates.
Tool categories at a glance
| Category | Questions it answers | Well-known examples |
|---|---|---|
| Search performance | Which queries and pages get impressions and clicks? Are pages indexed? | Google Search Console, Bing Webmaster Tools |
| Web analytics | What do visitors do after arriving? Which channels lead to enquiries or sales? | Google Analytics 4 (GA4) |
| Page speed and experience | How fast and stable are pages for real users and in lab tests? | PageSpeed Insights, Lighthouse, Chrome DevTools |
| Site crawlers | Which pages have broken links, redirects, missing tags or duplicates? | Screaming Frog SEO Spider, Sitebulb |
| Keyword research | What do people search for, and how competitive is it? | Google Keyword Planner, Google Trends, Ahrefs, Semrush, Moz |
| Backlink analysis | Who links to a site and how has that changed? | Ahrefs, Semrush, Moz, Majestic |
| Structured data testing | Is the markup valid and eligible for rich results? | Rich Results Test, Schema Markup Validator |
Google Search Console
Search Console is a free service from Google and the most direct source of information about how Google sees your site. Every site owner should verify their site there first.
- Performance: clicks, impressions, click-through rate and average position by query, page, country and device.
- Page indexing: which URLs are indexed and why others are excluded.
- URL Inspection: the indexed and live status of a single URL, including rendered HTML.
- Sitemaps, Core Web Vitals and Links reports for site-wide health.
- Manual actions and Security issues: warnings that need urgent attention.
Bing Webmaster Tools offers similar reports for Bing and can import sites verified in Search Console.
Google Analytics 4
GA4 measures behaviour on your site using an event-based model. For SEO, filter traffic by the "Organic Search" channel to see engagement and key events (the actions you mark as important, such as form submissions or purchases) from search visitors. Linking GA4 with Search Console lets you view query data alongside on-site behaviour.
PageSpeed Insights and Lighthouse
PageSpeed Insights shows two kinds of data for a URL. Field data comes from the Chrome User Experience Report and reflects real visitors, when a page or site has enough traffic. Lab data comes from a Lighthouse test run in a simulated environment.
Lighthouse is also built into Chrome DevTools and audits performance, accessibility, SEO basics and other areas. Lab tests cannot measure INP directly because no real user interacts with the page; they report Total Blocking Time as a related indicator. Use field data to judge Core Web Vitals and lab data to debug causes.
Site crawlers
A crawler visits your pages the way a search engine bot would and records what it finds: status codes, titles, meta descriptions, headings, canonical tags, internal links, page depth and duplicates. Screaming Frog SEO Spider is a widely used desktop crawler, and Sitebulb is another option with visual reports. Many research suites include a cloud-based site audit crawler as well.
Most crawlers can also render JavaScript, which helps when checking issues described in the guide to JavaScript and search. Crawl data is the backbone of any technical SEO audit.
Keyword and backlink research suites
Ahrefs, Semrush and Moz run their own web crawlers and collect search data to estimate keyword volumes, ranking positions, competitor traffic and backlink profiles. Google Keyword Planner, inside Google Ads, provides search volume data from Google, and Google Trends shows relative interest over time and by region, which is useful for seasonal topics such as Diwali gifting or exam results.
- Volume and traffic figures are estimates, and different tools often report different numbers for the same keyword.
- Authority scores such as Domain Rating, Authority Score or Domain Authority are proprietary vendor metrics. Google does not use them.
- Use these suites to compare options and spot trends, then check results against your own Search Console data.
For a method that works with any of these tools, read the keyword research guide.
Building a starter toolkit
- Verify the site in Google Search Console and Bing Webmaster Tools.
- Install GA4 and define your key events.
- Test important templates in PageSpeed Insights and Lighthouse.
- Crawl the site with a desktop or cloud crawler.
- Add a research suite when you need competitor, keyword or backlink data at scale.
Learning to read these tools, rather than just collecting reports, is a big part of what you practise when you study SEO online at SkillNewton, where learners use them on real projects.
Common mistakes
- Treating third-party traffic and volume estimates as exact figures.
- Chasing a vendor authority score instead of earning relevant links and traffic.
- Fixing every Lighthouse suggestion while ignoring real-user Core Web Vitals data.
- Buying several overlapping paid tools before using the free Google tools properly.
- Never linking Search Console with GA4, which hides how search visitors behave.
Frequently asked questions
Can I learn SEO using only free tools?
Yes. Search Console, GA4, PageSpeed Insights, Lighthouse, Keyword Planner, Google Trends and the free tiers of crawlers are enough to learn and practise most SEO tasks.
Why do Ahrefs and Semrush show different numbers?
Each tool uses its own crawler, data sources and models, so their estimates differ. Use one consistently for trends rather than mixing figures between tools.
Do I need a separate rank tracker?
Search Console shows average position for your queries. A rank tracker adds daily checks for chosen keywords and locations, which is helpful for competitive or local campaigns.