1 · See it
The agent view
The answer an agent receives about any domain, rendered for a person: each action’s decision and the reason.
Free SEO audit tool: the technical checks, plus what AI crawlers actually receive
In one sentence
An SEO audit tool checks whether a site can be crawled, understood and served quickly: robots.txt and sitemap, status codes, structured data, titles and descriptions, page weight and speed. CrawlCheck runs those checks and adds what most SEO audit tools leave out — the page as each named AI and search crawler actually receives it.
Type a domain. You get an A–F grade and a prioritised fix list covering the technical SEO basics — status codes, robots.txt, sitemap, structured data, page weight and speed — and the part most SEO audit tools skip: what Googlebot, GPTBot, ClaudeBot and PerplexityBot are each actually served. Free, no signup, nothing installed.
Measured
What the scan measures for this
Crawlability
robots.txt rules resolved per crawler, the sitemap and every child it declares, broken and redirected URLs, and links the homepage carries that the sitemap never declares.
Structured data
Every JSON-LD block parsed, the entities it declares, duplicate ids, missing identity fields, and whether the meta description and title say what the page is.
Content an engine can read
Visible words as a share of the page, the machine files that parse, and whether the text exists before JavaScript runs.
AI and search crawlers
The page fetched as each named crawler in the same second, compared with a normal browser: refused, challenged, thinner or identical.
Speed
Field data where Chrome publishes it, a lab reading where it does not, and first-party readings from your own visitors once you add one script.
For agents
What an agent is told about the same site
An agent does not read the report. It asks one endpoint before it reads, cites, connects or transacts, and gets a signed answer built from the same measurement.
2 · Call it
One endpoint
GET /api/v1/resolve?domain= returns the signed answer; preflight returns a decision and a receipt for one action.
3 · Check it
Without trusting us
Every answer is Ed25519-signed and logged; it verifies offline with the published key.
Workflow
The workflow
- Scan the domainAbout thirty read-only requests and twenty seconds for a site we have not seen before. Nothing is installed and nothing on the site changes.
- Read the grade and the fix listEvery row names the URL, the bytes and the rule that decided it. The fix list is already in priority order, crawler access first.
- Fix, then re-scanThe second scan is the proof. A licence keeps the dated history and tells you when a fixed row comes back.
- Audit more than the homepageThe depth crawl reads every URL the sitemap declares: orphans, undeclared pages, thin pages, duplicate titles and per-page status.
Free
Free tools for this
Each one is a single request to the domain you name, answered as text or a download. Put the domain on the end of the URL, or use the form on the tools page.
Compare your site with a competitorGrades side by side, the biggest section gaps, and the findings only one of you has.Test robots.txt for every AI crawlerEach named crawler resolved against your rules, with the group that actually applies to it.Local SEO: check your business recordWhat your site says about the business against what the directories print, then join the registry free.Reports for agenciesThe Agency plan keeps 40 client domains under continuous record, with client-safe branded reports you can hand over and alerts when a fixed problem returns.
Reading
Read next
- How to read a CrawlCheck report
- What a crawler actually receives
- The glossary: every term in the report, defined
Start from what you are checking
llms.txt auditdoes yours resolve, parse and match the site it describes?robots.txt for AI crawlerswhat yours actually permitsEntity map validatordoes your entitymap.json parse, and does every claim in it resolve?Technical SEO auditcrawl access, sitemap, hosts, links and speed, checked in one scanLocal SEO auditdoes your site say who you are, where, and does every listing agree?SEO audit reports for agenciesyour name on the report, the proof still attachedWhat is a website auditWhat is a website audit? What it checks, what it costs, and how to run one freeWhat is an SEO auditWhat is an SEO audit? The checks that matter, in the order to fix themAEO auditcan ChatGPT, Claude, Perplexity and Google reach, read and quote your site?
You cannot pay to improve a score. A licence adds the lists behind the counts and the record over time - never a better grade.
Questions about this page
QWhat is an SEO audit?
A check of the things that decide whether search engines can crawl, understand and rank a site: crawl access, sitemap, status codes, structured data, titles and descriptions, content quality and speed. A good audit names the exact URL and the reason for every problem and puts the fixes in order.
QWhat is a website audit?
The broader version: SEO plus accessibility, security headers and how the site performs for real visitors. The free CrawlCheck scan covers the SEO and machine-readability half on the homepage; the depth crawl covers every URL the sitemap declares.
QIs CrawlCheck free?
Yes. Every scan is free with no signup and no daily limit, including the full report and fix list. Paid plans add continuous watching, dated history, client-safe branded reports for agencies and the API.
QHow is it different from Semrush, Ahrefs, Screaming Frog or Moz?
Semrush Site Audit, Ahrefs Site Audit, Screaming Frog SEO Spider and Moz Pro crawl a site as one crawler and report on-page and technical SEO in depth. CrawlCheck fetches the page as each named AI and search crawler at the same moment and compares what each was served, which is how a site that ranks in Google can still be invisible to ChatGPT or Claude. Many teams use one of those tools for keyword and link data and CrawlCheck for the machine layer. CrawlCheck publishes this page.
QHow is it different from WooRank or SEOptimer?
WooRank and SEOptimer give an instant one-page SEO report with a score. CrawlCheck also gives a one-page report and a grade, adds the per-crawler comparison and signs every result, so the same reading can be checked later by anyone. CrawlCheck publishes this page.
QIs there an SEO audit tool for agencies?
Yes. The Agency plan keeps 40 client domains under continuous record, with client-safe branded reports and receipts you can hand over, regression alerts across every domain and the API included.
QDoes it do local SEO audits?
Yes. The scan checks the business name, phone and address in the page and its structured data, and the listing check compares them with what the directories print.
QIs there an open-source version?
The robots.txt reader is open source as crawlcheck-core on GitHub; the scanner itself runs as a free hosted service.