The SEO tool market wants you to believe you need a $500/month stack to audit a website.
You don't. For most sites, you can run a thorough audit with one paid tool and a couple of free ones. This article is the honest comparison — what each tool is genuinely good at, what overlaps, and where free tools are perfectly sufficient.
The free tools you should always use
These are non-negotiable and they're free. Start here before paying for anything.
Google Search Console (free) — the source of truth
This is the only tool that shows you how Google itself sees your site. Indexation status, actual search queries, ranking positions, Core Web Vitals, manual actions, and the links Google credits.
No paid tool replaces GSC, because no paid tool has Google's actual data. Whatever else you use, GSC is the foundation. Most "audit findings" should be verified against it.
Google Analytics (free) — behaviour data
For understanding what visitors actually do once they arrive. Essential for connecting SEO to outcomes.
Google PageSpeed Insights (free) — Core Web Vitals
Real Core Web Vitals data plus specific fix recommendations. You don't need a paid tool for performance auditing.
Screaming Frog (free up to 500 URLs) — crawling
The free tier crawls 500 URLs, which covers most small-to-medium sites entirely. Find broken links, redirect chains, missing titles, duplicate content, crawl depth, and orphan pages.
For most sites, these four free tools cover 70% of a complete audit.
The paid tool worth having: one of Ahrefs or Semrush
You need exactly one of these, primarily for one thing free tools can't do well: backlink data and competitor analysis.
Ahrefs — best-in-class backlink index. If your audit's focus is links and competitor gaps (usually the real ranking ceiling), Ahrefs is the pick.
Semrush — broader all-in-one. Slightly weaker backlink data than Ahrefs, but stronger on keyword research, PPC data, and reporting if you want one tool for everything.
You don't need both. They overlap 80%. Pick one based on whether you lean toward links (Ahrefs) or all-in-one breadth (Semrush). Both run $100-$200/month.
Tools you probably don't need
Honest take on the rest:
Dedicated "SEO audit" tools (Sitebulb, etc.) — Sitebulb is genuinely excellent and produces beautiful audits. But for most people, Screaming Frog + GSC covers the same ground. Worth it if you do audits professionally; overkill if you're auditing your own one site.
"Toxic link" / disavow tools — mostly fear-marketing. Google ignores most bad links automatically. You rarely need these (more on that in the link-audit space).
Rank trackers (standalone) — GSC shows your actual positions for free. A dedicated rank tracker is a nice-to-have for daily monitoring, not an audit essential.
All-in-one "SEO platforms" at $300-$500/month — usually bundling things you already have. Resist the upsell unless you're running an agency at scale.
The honest tool stack by use case
Auditing your own single site: GSC + GA + PageSpeed + Screaming Frog (free) + one of Ahrefs/Semrush. Total: ~$100-$200/month, most of it free.
Freelance SEO with a few clients: The above, plus maybe Sitebulb for client-facing audit reports. ~$150-$250/month.
Agency at scale: Ahrefs OR Semrush (team plan) + Screaming Frog (paid) + Sitebulb + a rank tracker. This is where the bigger stacks justify themselves.
For 90% of people reading this, the answer is: the free tools + one paid backlink tool. That's it.
The AI layer (2026 addition)
New in 2026: AI dramatically speeds up the interpretation of audit data.
Export your crawl data, GSC data, or backlink report, paste it into ChatGPT or Claude with the right prompt, and get a prioritised, plain-English summary in seconds — instead of manually sifting through thousands of rows.
This doesn't replace the tools (you still need them to gather the data) but it collapses the analysis time dramatically. The free AI SEO Prompt Library includes a full set of technical-audit interpretation prompts for exactly this.
The takeaway
Don't let tool marketing convince you that auditing requires an expensive stack. It requires:
- Google's free tools (the source of truth)
- A free crawler (Screaming Frog)
- One paid backlink tool (Ahrefs or Semrush)
- AI to speed up interpretation (ChatGPT/Claude + good prompts)
That stack runs a more thorough, more accurate audit than most $500/month platforms — because it's built around Google's actual data, not a vendor's proxy metrics.
What's next
The tools gather the data. Knowing what to do with it is the skill. The free 25-point SEO audit checklist on this site tells you exactly what to look for and in what order.
Or request a free audit and I'll run the tools on your site and tell you the 3 biggest gaps live — no stack required on your end.
