Website SEO Checker: What a Good Audit Finds and Fixes

A website SEO checker fetches your pages the way a search crawler does and lists what stops them from ranking. That means pages that can’t be crawled or indexed, missing or duplicate titles and descriptions, broken links, redirect chains, missing structured data, thin content and, now, whether AI crawlers can read the site. The useful ones rank the problems so you fix the few that matter first, instead of handing you a score and 140 warnings.

You run a free SEO audit, get a number like 71 out of 100, fix the easy warnings and close the tab. Traffic doesn’t move, because the warnings that cost rankings were three lines in a long report and looked like all the others.

What should a website SEO checker test?

Eight areas, in roughly this order of weight. If a checker skips the first two, the rest doesn’t matter much.

Area	What it checks	Typical fix
Crawl and index	robots.txt, sitemap, HTTP errors, noindex, canonicals, soft 404s, orphan pages	Remove a stray noindex, add pages to the sitemap
On-page	Title, meta description, one H1, heading order, language, viewport	Rewrite a title to put the keyword first, under 60 characters
Content	Thin pages, duplicate pages, whether the page answers its query	Merge two thin posts into one
Links	Broken internal links, links to redirects, generic anchor text	Point links at the final URL, name the target in the anchor
Structured data	JSON-LD present, valid and complete for its type	Add the required fields to the Article or Product schema
AI readiness	AI crawlers allowed in robots.txt, llms.txt, answer-first content	Stop blocking the AI crawlers you want citing you
Performance	Server response time, page weight	Cache the page, cut heavy HTML
Security	HTTPS, HSTS, mixed content	Redirect every HTTP URL to HTTPS

The order matters because a perfect title on a page Google can’t index is worth nothing. A good checker groups findings by area and severity so you can see that.

Which free SEO audit tools cover what?

You can cover most of the table for free, with three tools and some patience:

Google Search Console tells you which pages are indexed, why the others aren’t, and which queries each page shows up for. It’s the only source of what Google actually did with your site. Set it up first.
PageSpeed Insights (and Lighthouse inside Chrome) measures loading and Core Web Vitals and runs a short on-page SEO checklist for one page at a time.
A crawler walks the whole site and finds broken links, redirect chains, duplicate titles and orphan pages, which one-page tools can’t see.

What the free tools don’t do well is judgment: whether the page answers the question it targets, whether the title promises what the page delivers, whether the facts are sourced. That’s the part the guide to whether AI content hurts SEO says decides most demotions.

A full SEO suite is the better pick if you need backlink data, rank tracking or keyword ideas at scale. A checker answers a narrower question: what’s wrong with these pages, and what do I fix first.

How do you run an SEO audit step by step?

Start with Search Console. Look at the pages report for anything “crawled, not indexed” or “excluded by noindex”. Those are your first fixes.
Crawl the site. 25 pages is enough for a small site, 100 for a blog with a few dozen posts. Fix broken internal links and redirect chains in one pass.
Check every page that matters for one query. Title with the keyword first and under 60 characters, a meta description of 110 to 160 characters, one H1, a direct answer near the top. The meta description guide covers the snippet.
Check for pages competing for the same query. Two posts on the same intent split the clicks. The keyword cannibalization guide shows how to find and merge them.
Check AI crawler access. Some CDNs and security plugins block AI crawlers by default, so a site can block them without anyone deciding to. If you want to be cited in AI answers, let them in. The llms.txt guide covers the optional file that sits next to robots.txt.
Fix in order of severity, then re-check. Critical and high first. A re-crawl a week later tells you whether the fixes held.

What does an on-page SEO checker miss?

Most on-page checkers test the parts that can be counted: length, presence, duplicates. They pass a page with a perfect title and a description that matches nothing a buyer types, or a post that has every heading in the right order and never answers the question.

The miss is the query. A page is only “optimized” for something. Without a target query, a checker can tell you the title is 58 characters, not that it’s the wrong 58 characters. Pick the query first (how to choose target keywords), then check the page against it. The internal linking guide covers the other thing counting tools tend to underrate: which pages link to the one you want to rank.

How does the Copix SEO Engine check a website?

Copix is an MCP server, so the audit runs inside the AI you already use (Claude, ChatGPT, Cursor or Claude Code) and your AI can start fixing as soon as the report lands. On Copix Complete you ask in plain words:

Audit https://example.com/pricing for “invoicing software for freelancers”.

The SEO Engine has three ways to check a site:

Page audit (3 credits): one live page against the page rules, its schema, its AI-citation readiness, robots.txt for search and AI crawlers, and llms.txt on the host. With a query, it also judges whether the page fits and answers it. You get a score, a grade, the score per area and every finding with its evidence and fix.
Crawl (10 credits for 25 pages, 30 for 100): the whole site against 52 rules, with broken links, redirects, orphan pages, a page inventory and the top 20 actions in order.
Draft check (2 credits): a post before it’s published, against its query and our house rules.

Every call tells you the price in credits and waits for your yes. The report says what ran and what was skipped next to the score, so a partial check never reads as a full one.

It doesn’t measure Core Web Vitals: use PageSpeed Insights for that. For links pointing to your site, the backlinks mode lists a sample of them; Search Console has the full list.

What does it cost?

The SEO Engine is part of Copix Complete: $29 a month or $290 a year, with 1,500 credits every month that roll over up to three months. At 3 credits a page audit, a month’s credits cover 500 of them. Complete also has the GEO Engine (whether ChatGPT, Claude, Gemini and Perplexity cite you), the Conversion Engine and the Ads Engine, plus Basic’s write, review and saved brief.

Your first plan starts with a 14-day free trial: card at checkout, nothing charged for 14 days, then $29 a month unless you cancel from your account. Complete gets its full 1,500 credits on day one.

Start your 14-day free trial of Copix Complete, or compare the plans first.

FAQ

What is the best free website SEO checker?

Start with Google Search Console: it’s Google’s own report of which pages it indexed, which it left out and why. Pair it with PageSpeed Insights for speed and a crawler for broken links and duplicates.

How often should I run an SEO audit?

A full crawl once a month is plenty for most small sites, plus a page check whenever you publish or change an important page.

Is a 100 out of 100 SEO score worth chasing?

Rarely. A score weights every rule the same way its tool chose to. Fix what blocks indexing and what affects your pages for their target queries; the last few points are usually minor warnings.

Can an SEO checker tell me why my traffic dropped?

It can find a technical cause, such as a page that started returning noindex or a broken redirect. For drops with no technical cause, compare queries and pages in Search Console before and after the date.

Does the Copix audit change my site?

It only reads public pages. Your AI suggests the fixes and you decide what goes live.