There are a lot of free tools that promise to tell you what’s wrong with your website’s SEO, and most of them are genuinely useful — for the specific thing they’re built to check. The confusion usually starts when someone runs one tool, gets a score, and assumes it’s the whole picture. It isn’t, because no single free tool covers everything. Here’s what the main categories actually do, and where each one stops.
Page speed tools (PageSpeed Insights and similar)
These load your page and measure how fast it actually renders — time to first paint, how long until someone can click something, whether images are bloated. Google’s own PageSpeed Insights is the standard here, and it’s the same engine behind our own website speed test.
What it shows: a genuinely accurate, technical measurement of load performance on mobile and desktop, plus specific fixes (compress this image, defer that script).
What it misses: everything about your actual content. A page can score 100/100 on speed and still say nothing useful, target the wrong search, or be missing from Google’s index entirely. Speed is one ranking signal among many — a fast page that answers no one’s question still won’t rank.
Crawl-based SEO checkers
These tools crawl your site the way a search engine does and check the on-page and technical basics: titles, meta descriptions, duplicate content, broken links, missing alt text, sitemap coverage. Our own free SEO check sits in this category, and we’ve written more about exactly what it looks at in what does an SEO audit actually check.
What it shows: whether Google can technically crawl, read, and make sense of your site — the unglamorous groundwork that has to be right before anything else matters.
What it misses: whether your site is actually a good answer to what people are searching. A crawler can confirm every page has a title tag; it can’t tell you whether the title is compelling, accurate, or matches what a real customer types into Google.
Google Search Console
Free, and arguably the most useful tool on this list, but it’s not an audit — it’s a direct line into what Google itself thinks about your site, after the fact. It shows which searches actually bring people to your site, how often they click, which pages are indexed, and any pages Google’s flagged with a problem.
What it shows: ground truth. Not an estimate or a simulation — the real data about your real site, from the source that matters.
What it misses: anything about a site that isn’t set up yet, or hasn’t been crawled recently. It’s a mirror, not an X-ray — it tells you what’s already happened, not what will happen if you change something.
”All-in-one” SEO scoring tools
Plenty of tools bundle a score out of 100 covering a mix of speed, on-page basics, and sometimes backlinks — often gated behind a signup or a paid tier for the detail. The single score is the appeal and also the trap.
What it shows: a rough, quick gut-check, useful for noticing if something’s badly broken.
What it misses: nuance. A single number can’t tell you that one flagged issue is genuinely urgent (a noindex tag left on by accident) while another barely matters for a small local site (a minor keyword-density warning). Treat the score as a prompt to look closer, not a verdict.
Why running more than one tool is worth it
Each category above checks a different layer — speed, technical crawlability, real search performance, and a rough overall gut-check — and none of them substitutes for the others. A site can pass a speed test and fail a crawl check, or crawl perfectly and still not rank because the content doesn’t match what anyone’s actually searching. Running a speed test and a crawl-based check together, then cross-referencing both against what Search Console shows is actually happening, gives a far more honest picture than trusting any single score.
What none of them do
No free tool — ours included — reads your site the way a customer does and judges whether it’s actually convincing. Whether your homepage explains what you do clearly, whether someone would trust you enough to call, whether the price on the page matches the quality of the photos — that’s a human judgement, not a crawl result. The tools are the diagnostic step. What you do with the findings is the part that actually needs a person.
The honest answer
Free tools are worth running — they catch real, fixable problems for no cost. Just don’t mistake a green tick on one tool for a clean bill of health across the board. If you want the technical crawl-based check specifically, our free SEO check is a solid starting point; pair it with a speed test and an honest look at Search Console, and you’ll have a genuinely complete picture rather than one slice of it.