Best Free SEO Auditing Tools Available In 2024

Ten blue links used to be the whole game. Now your site competes not just with competitors but with AI answers that summarize the results page before anyone clicks — and if an AI engine can't read or cite your pages, you're invisible in that conversation.

Search Engine Journal's local SEO audit guidance is blunt about the shift: LLMs and AI Overviews now determine visibility, and informational search results are "largely being dominated by AI summaries." That changes what an audit needs to check, not just how often you run one.

The technical bar has quietly risen too. Over-reliance on JavaScript is now flagged as particularly detrimental for LLM visibility, since some LLMs do not execute JavaScript. If your site renders its content client-side, an AI engine may see an empty page — even when Google ranks you fine.

Most small business sites have never been audited at all. They were built once, launched, and left alone. That means broken internal links, missing schema, thin location pages, and mobile usability problems accumulate silently while the owner wonders why the phone stopped ringing.

Here's what a modern audit needs to cover that a 2019 checklist didn't:

• AI citability — whether ChatGPT, Perplexity, and Gemini can read, understand, and reference your content
• JavaScript rendering — whether your pages show anything at all to non-executing crawlers
• Schema and structured data — the machine-readable signals AI engines lean on
• Commercial-intent keywords — SEJ advises prioritizing these in audits, since AI summaries now absorb most informational queries

The tool vendors have noticed. SEOptimer now reports Google AI Search Rankings alongside factors like LLM accessibility and citability, and Semrush frames a healthy site as one that increases the chances its pages are "used, cited, or referenced by AI systems."

But be clear-eyed about what free tools actually give you. Free tiers are deliberately limited funnels into paid products. Semrush allows one free check per day. Backlinko caps you at three. Screaming Frog stops crawling at 500 URLs and locks JavaScript rendering behind its paid licence. A free audit is a snapshot, not a diagnosis — useful for spotting obvious problems, not for fixing them.

That's the gap most audits leave open: they tell you what's broken, then hand you a PDF and wish you luck. It's why at AI Business Sites we treat auditing as an ongoing loop rather than a one-time event — tracking not just Google and Bing rankings but whether the AI engines cite you at all, week after week, and fixing what the audit finds.

Start with the free tools in this guide. They'll tell you where you stand. What you do next is the part that actually moves rankings.

Most free SEO checkers audit one page at a time. Screaming Frog's SEO Spider is the exception: it's a genuine full-site crawler you can download and use without creating an account, and it finds issues the point-and-click tools never touch.

The free tier crawls up to 500 URLs per run and flags more than 300 SEO issue types, each with priority scoring so you know what to fix first. It crawls breadth-first the way Googlebot does, and it renders JavaScript sites using headless Chromium — a big deal, since some LLMs don't execute JavaScript at all, making heavy JS sites invisible to AI engines. The free version also checks spelling and grammar in 25+ languages.

The practitioner endorsements are hard to ignore. Mike King of iPullRank says he uses it "every single day," calling it "incredibly feature-rich, rapidly improving." Aleyda Solis of Orainti describes it as her "go to" tool for initial SEO audits and quick validations — "powerful, flexible and low-cost." Glenn Gabe calls it "the Swiss Army Knife of SEO Tools."

What the free version doesn't do:

• Crawl beyond 500 URLs per run
• Save crawls for later comparison
• Configure advanced crawl settings
• Render JavaScript beyond the free limits, run custom extraction, or connect API integrations

Removing those limits requires the paid licence at £199 per year, per the official product page. That's a one-time annual cost, not a monthly subscription — a fraction of what all-in-one suites charge. (A third-party comparison cites $259/year, but the vendor's own page is authoritative.)

For a small business with a site under 500 pages, the free tier effectively covers a complete technical audit at zero cost. If you're running a larger site, you can still crawl it in sections — or focus the 500-URL budget on your most important commercial pages first.

The trade-off is your time. Screaming Frog hands you raw findings — broken links, redirect chains, missing metadata, duplicate content — and you have to interpret and fix them yourself. It's the right tool when you want depth; it's not a done-for-you solution. That's the distinction we draw at AI Business Sites: free tools tell you what's broken, but someone still has to do the fixing. If you'd rather have technical SEO handled as part of a managed system than spend a Tuesday crawling your own site, book a free strategy call and we'll walk through what a fully managed approach looks like.

For a genuinely free full-crawl audit, though, nothing else in the 2024 roundup comes close.

Not every audit needs a full crawl. Sometimes you just want to paste a URL, get a score, and know whether something is badly broken — without creating an account or sitting through a sales demo. That's exactly the niche these single-page checkers fill.

Backlinko's Free SEO Checker is the strongest zero-commitment option in this category. It runs 38 checks across 8 categories and returns a score from 0 to 100, with mobile usability making up the largest single category at 10 checks. You get three free checks per day, no signup and no credit card required — and because it's powered by Semrush data, the results carry real weight despite the quick format.

Semrush's own free checker works the same way but with a tighter limit: one free check per day, covering on-page and technical signals. The framing is telling — Semrush describes a healthy site as one that increases "the chances that your pages can be used, cited, or referenced by AI systems," a clear sign of where audit tools are heading in 2024. The free check is a snapshot; the paid Site Audit runs 140+ checks and crawls up to 20,000 pages per project.

SEOptimer rounds out the trio with an instant URL audit that's popular with beginners. One reviewer notes it's "easy to use and great for people starting out in SEO," and it has expanded into AI/GEO visibility — reporting on factors like LLM accessibility and citability. A free 14-day trial of Premium is available if you want more depth.

• Backlinko: 38 checks, 0–100 score, 3 checks/day, no signup
• Semrush: 1 check/day, on-page and technical signals, AI-citation framing
• SEOptimer: instant URL audit, AI/GEO visibility reporting, 14-day Premium trial

Be honest with yourself about the limits: these are deliberately capped funnels into paid products. Backlinko says it outright — the free tool gives "a quick snapshot," while the full picture requires Semrush. A free Semrush account does add AI visibility tracking for up to 10 queries per day, which is a genuine bonus if you're curious whether ChatGPT or Perplexity ever mention your business.

For a small business owner, these checkers are best used as a first diagnostic — a way to confirm whether your site has obvious problems before deciding where to invest. If a quick scan reveals structural issues across multiple pages, fixing them once, properly, usually beats running daily spot checks. That's the difference between auditing a page and maintaining a site: the tools here tell you something's wrong; ongoing SEO work is what actually fixes it.

Before you spend a dollar on any SEO software, Google will hand you the most trustworthy audit data available — straight from the source that ranks you. These tools are free forever, require no account upgrade, and come with zero vendor lock-in, which is why they remain the baseline every serious marketer runs first.

Google Search Console anchors the stack. It reports directly on Core Web Vitals, Page Experience signals, and your backlink profile — the same data Google itself uses to evaluate your site, as noted in Search Engine Journal's local SEO audit checklist. Pair it with Lighthouse and PageSpeed Insights for performance auditing, and the Rich Results Test plus the Schema.org validator to confirm your structured markup is eligible for enhanced search features.

• Search Console — Core Web Vitals, Page Experience, and backlink monitoring in one dashboard
• Lighthouse and PageSpeed Insights — lab and field performance data for every key page
• Rich Results Test and Schema.org validator — verify structured data before Google sees errors

One caution from the research: over-reliance on JavaScript is "particularly detrimental for LLM visibility, as some LLMs currently do not execute JavaScript," per Search Engine Journal. If your content only renders through JS, both traditional crawlers and AI engines may see an empty page — a silent rankings killer that free Google tools will surface.

The local SEO audit deserves its own pass. Getpin's step-by-step local audit guide argues that checking Google alone isn't enough — your audit should also cover Apple Business Connect and Bing Places. The stakes are real: Apple Maps is the default maps app on over 1 billion active Apple devices, and Bing holds roughly 4.45% of global search share.

The numbers make the case for prioritizing this. According to Google data cited by Getpin's local audit guide, 76% of people who conduct a local search on their phone visit a related business within 24 hours, and 28% of those searches result in a purchase. Listings with photos see 42% more direction requests and 35% more website clicks.

Your local checklist should cover NAP consistency (name, address, phone identical everywhere), review profiles across platforms, and the three local ranking factors: relevance, proximity, and prominence. This is exactly the groundwork a done-for-you service like AI Business Sites handles at launch — Google Business Profile, Search Console, and sitemaps configured as part of the initial build — because a correct baseline beats a fancy audit on a broken foundation.

Run the Google-native stack first, fix what it reveals, and only then layer in third-party tools for the deeper crawling work.

A few years ago, "SEO audit" meant checking title tags and broken links. In 2024, the question has changed: when someone asks ChatGPT, Perplexity, or Gemini for a recommendation in your category, does your business appear in the answer — or does a competitor? Search Engine Journal notes that informational search results are now largely dominated by AI summaries, which makes AI citability a first-class audit item, not a novelty.

The good news is that free tools have caught up. Three stand out for checking your AI visibility without spending anything:

• Backlinko's AI Brand Visibility Checker — tests whether ChatGPT, Gemini, and Perplexity can find and reference your brand, alongside an AI Agent Readiness Checker for the same zero-signup, three-checks-per-day model as its main SEO checker.
• Semrush's AI Search Visibility Checker — a free Semrush account tracks AI visibility for up to 10 queries per day, showing whether AI systems can use, cite, or reference your pages.
• SEOptimer's GEO reporting — the platform has expanded into AI and generative-engine visibility, reporting Google AI search rankings plus factors like LLM accessibility, identity, and citability.

Two technical caveats are worth flagging before you run these checks. First, JavaScript-heavy sites are at a real disadvantage: some LLMs currently do not execute JavaScript at all, so content locked behind scripts may be invisible to the very engines you're auditing. Second, unlinked brand mentions matter more than they used to — SEJ reports they play a significant role in AI visibility, so an audit should look beyond backlinks.

Here's the honest trade-off, though. Every free tool in this category — and every free tool in this entire roundup — is a snapshot. You run the check, you get a report, and that report is accurate for roughly the moment you downloaded it. AI answers shift weekly as models re-crawl and re-rank; a citation you won today can quietly disappear next month without a single alert. Free tools are excellent for establishing a baseline and spotting obvious gaps, but continuous auditing is where the real work lives — and where manual checks stop scaling.

That's the gap managed systems are built to fill. AI Business Sites includes an SEO Growth Engine in every build that runs a weekly measure-target-edit-publish-report loop, including AI-citation share-of-voice monitoring across ChatGPT, Perplexity, Google AI Mode, and Gemini — the same questions these free tools ask, answered every week without you lifting a finger, alongside a growth report that lands in your inbox showing what moved.

If you'd rather have the baseline conversation first, book a free strategy call. Thirty minutes, no obligation, no sales pitch — just a look at where your site stands with both Google and the AI engines, and what closing the gap would actually take.