What Does a Free SEO Audit Actually Check? A Plain-English Breakdown
Type "free SEO audit UK" into Google and you'll get a hundred tools that spit out a red-amber-green scorecard in thirty seconds. Most check a handful of surface metrics and call it a day. A proper audit — free or paid — needs to look at four distinct layers of your site, because a problem in one layer can quietly undo the good work you're doing in another. Here's what should actually be on the list.
On-page and content
This is the layer most tools get right, at least partially. It covers title tags, meta descriptions, heading structure, keyword targeting and internal linking. A good audit won't just flag that a page is "missing a meta description" — it'll tell you whether your titles and headings actually match what people are searching for, and whether your own pages are competing against each other for the same terms (a surprisingly common problem once a site passes fifty pages).
It should also flag thin or duplicate content, orphan pages with no internal links pointing to them, and whether your top pages genuinely answer the query or just skirt round it. Word count isn't a ranking factor on its own, but pages that don't fully answer the question tend to get outranked by ones that do.
Technical foundations
This is where free tools tend to fall over, because it requires actually crawling the site rather than scanning the homepage. A proper technical check covers crawlability (robots.txt, XML sitemaps, canonical tags), indexing status in Google Search Console, site speed and Core Web Vitals, mobile usability, broken links and redirect chains, and structured data for products, articles and local business listings.
Redirect chains in particular are a silent killer — we regularly find sites losing crawl budget and link equity to three or four redirect hops that built up over years of undocumented migrations. A decent audit surfaces these by URL, not as a vague "redirects found" count.
Local and off-page signals
If you're a business that serves a physical area — a trade, a clinic, a shop with a catchment — local signals matter as much as on-page content. That means your Google Business Profile completeness and category accuracy, NAP (name, address, phone) consistency across directories, review volume and response rate, and whether you've got proper local landing pages for each area you serve, rather than one generic "areas we cover" page trying to rank for six different towns at once.
Off-page more broadly means backlinks: not just how many you have, but their relevance, and whether any look spammy enough to warrant a disavow. Quantity without relevance does very little for UK local rankings these days.
AI search visibility
This is the newest layer, and the one almost no free tool checks properly yet. People increasingly get answers from ChatGPT, Perplexity and Google's AI Overviews instead of clicking through ten blue links. Whether your business gets mentioned in those answers depends on different signals to classic SEO: whether your content is structured so an LLM can lift clear, quotable facts from it; whether you've got an llms.txt file guiding AI crawlers to your best content; and whether your brand and offering are described consistently enough across the web that an AI system can confidently cite you.
A genuinely useful audit today tells you not just how you rank in Google, but whether you show up — and how you're described — when someone asks an AI assistant a question your business should be answering.
What a good report gives you
The output should read as a prioritised list, not a wall of metrics: what's actively costing you rankings now, what's a slow leak worth fixing this quarter, and what's fine to leave. If a report doesn't tell you what to do first, it's a diagnostic without a doctor.
At Web-ly we build this AI visibility layer into every audit through Sentinal, alongside the standard technical, on-page and local checks — because ranking well in Google and being cited well by AI increasingly aren't separate jobs. They're the same job, seen from two angles.