Guides · 2026-10-08 · By VSNARY | Emmanuel Orta · 0 views
AI website audit tools compared: Semrush, Ahrefs, Screaming Frog, Sitebulb and CrawlCheck
“AI website audit” is sold as one thing and means two: a tool that uses AI to read its own findings, and a tool that audits what AI crawlers and agents actually receive from your site. Which of the five does which, what each costs, and how to pick for a small business, an e-commerce site or an agency.
Four of the five tools use AI to summarise or extend a classic technical SEO audit: Semrush Site Audit (from $139/month, with an AI Search Site Audit view), Ahrefs Site Audit (included in Ahrefs Free; paid plans from $29/month), Screaming Frog (free to 500 URLs, £199/year, with custom AI prompts during a crawl) and Sitebulb (MCP access into Claude and ChatGPT). CrawlCheck answers a different question: what GPTBot, ClaudeBot, PerplexityBot, Googlebot and other AI clients are actually served by your site, as a free A–F audit with monitoring from $29/month. Most sites need one of the first four for on-page work and CrawlCheck for the AI access question.
Disclosure: CrawlCheck publishes this comparison and is one of the products in it. Every price and feature claim about another company comes from that company’s own pricing or product page, read on 8 October 2026. Where CrawlCheck does less than a competitor, the page says so.
Search for an AI website audit tool and the results are two products wearing one label. The first is a technical SEO audit with a model attached: it crawls your pages, lists the usual issues, and uses AI to summarise, prioritise or let you query them. The second audits the site as AI sees it: it fetches your pages as GPTBot, ClaudeBot and the rest, and reports what each one was served. A site can score well on the first and be invisible on the second, because the first never asks whether an AI crawler gets the page at all.
Side by side
| Tool | What the audit crawls | The AI part | Starting price | Free tier |
|---|---|---|---|---|
| Semrush Site Audit | Your whole site, from Semrush’s cloud, 140+ checks | An AI Search Site Audit view: issues that can reduce visibility in LLMs and AI results; MCP access | $139/month (Pro), $117.33 billed annually | 7-day trial; one free SEO Checker run a day |
| Ahrefs Site Audit | Your whole site, from Ahrefs’ cloud, 170+ issues | AI Content Helper is a separate tool; Bot Analytics shows bots in your logs | $29/month (Starter); Lite $129 | Site Audit is included in Ahrefs Free |
| Screaming Frog SEO Spider | Your whole site from your desktop; renders JavaScript | Custom AI prompts with OpenAI, Gemini, Ollama and Anthropic while crawling; can crawl as a custom user agent | £199/year | 500 URLs per crawl |
| Sitebulb | Your whole site from desktop (Lite 10,000 URLs; Pro 500,000) or cloud | MCP access: bring audits into Claude and ChatGPT | Cloud from £95/month; desktop prices on request | Trial |
| CrawlCheck | Your homepage and machine files, fetched as 12 crawler identities plus a browser control, from outside | The audit is of AI access itself: what each crawler was served, robots.txt groups, llms.txt, entity data, signed result | Watch from $29/month; API from $99/month | Free A–F audit, every finding named, no account |
What each one answers
Semrush and Ahrefs: the SEO audit, with AI reading it
Both crawl every page from their own cloud and report the classic list: titles, duplicates, indexability, redirects, structured data, Core Web Vitals. Semrush adds an AI Search Site Audit view that flags issues it associates with visibility in LLMs and AI-driven results, and both now expose their data to AI assistants through MCP. What neither does is fetch your site as GPTBot or ClaudeBot: the crawl arrives as Semrush or Ahrefs, so a firewall rule that challenges AI crawlers and lets SEO crawlers through will never show up in the report. Ahrefs’ Bot Analytics is the exception that proves the point: it shows which bots reached you, from your logs, after the fact.
Screaming Frog and Sitebulb: desktop crawlers, deeper than anything here
For on-page work at scale, these two go further than the others: full-site crawls, JavaScript rendering, every link and header on every page. Screaming Frog can run a prompt against each page as it crawls, and can be set to crawl as a custom user agent, so one identity per crawl is possible. Sitebulb’s AI feature is MCP access, which puts the audit in front of Claude or ChatGPT rather than changing what is audited. Our separate comparison covers why one identity per crawl misses access problems that only show when several identities are compared on the same URL.
CrawlCheck: the audit of what AI is served
CrawlCheck does not crawl your whole site and does not list on-page issues. It fetches the homepage and the machine files (robots.txt, sitemap, llms.txt, entity data) as twelve named crawler identities and a browser, from outside, and reports what each was served: who got a 200 with content, who got a challenge page, which robots.txt group each name actually reads, whether the entity data resolves to one business. The result is a free A–F grade with every finding named, signed so an AI agent can verify it. It is built for the agentic web question, not the on-page one.
How to pick
| You are | Use | Why |
|---|---|---|
| A small business with one site | CrawlCheck free audit, plus Ahrefs Free for on-page | Both cost nothing; the first answers whether AI can read you, the second lists what to fix on the page |
| An e-commerce site | Screaming Frog or Sitebulb, plus CrawlCheck | Thousands of product pages need a full crawl; the AI access check is per-site and cheap to add |
| A startup on a budget | Ahrefs Starter ($29) or Screaming Frog free, plus CrawlCheck free | Under $30 a month covers both questions |
| An agency with many clients | Semrush or Ahrefs for reporting; CrawlCheck API for AI access across every client | The suites report and white-label; the API ($99/month) runs the AI access check at scale |
Where CrawlCheck is weaker
- No full-site crawl: the on-page issue list that every other tool here produces is not something CrawlCheck provides.
- No keyword, backlink or rank data; none of the SEO suite.
- No desktop app and no JavaScript rendering of your pages; it reads what the server sends, by design.
If you need one tool, it is one of the other four. If you need to know what AI crawlers and agents are served, that is the one question those four do not ask, and the one CrawlCheck exists for.
How this comparison was made
Prices and features are from each vendor’s pricing or product page on 8 October 2026: Semrush’s SEO Toolkit pricing page, Ahrefs’ pricing and Site Audit pages, Screaming Frog’s SEO Spider page and Sitebulb’s pricing page. No third-party review data was used. Prices change; the vendor page is the source of truth.
Every figure above came out of CrawlCheck.
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Questions this post answers
What is the best AI website audit tool for a small business?
For most small businesses, two free tools cover both questions: CrawlCheck’s free A–F audit shows what AI crawlers and agents are actually served by the site, and Ahrefs Free includes a Site Audit for on-page issues.
Does Semrush Site Audit check AI crawlers?
Semrush Site Audit crawls as Semrush and includes an AI Search Site Audit view that flags issues associated with visibility in LLMs. It does not fetch your site as GPTBot, ClaudeBot or other named AI crawlers, so access problems that affect only those crawlers are outside what it can see.
What is the difference between an AI SEO audit and an AI crawler audit?
An AI SEO audit is a classic technical audit that uses a model to summarise or extend its findings. An AI crawler audit fetches the site as the AI crawlers and agents themselves and reports what each was served. The first finds on-page issues; the second finds whether AI can reach and read the page at all.
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