Comparison
Free SEO audit tools compared, including Semrush alternatives
No single free SEO audit tool replaces Semrush, because Semrush's real moat is its keyword and backlink databases, not its auditing. The auditing side is largely reproducible for free: pair a page-level SEO and GEO auditor with Search Console for index data and PageSpeed Insights for Core Web Vitals, and you cover most of what a paid site audit reports.
Written by Vasa, GEO & AEO specialist · Last updated
What each free tier actually covers
| Tool | Free access | Strongest at | Where it stops |
|---|---|---|---|
| IMVASA Audit Tool | Fully free, no signup | SEO plus a full GEO/AI-search layer, schema validation with source line numbers, and a public MCP server. | Page-level by default; deep mode crawls a small sample of sitemap URLs rather than a full site crawl. |
| Google Search Console | Free, requires site verification | The only source of your real Google impressions, clicks, queries and index coverage. | Reports what already happened. It does not audit a page you have not published or do not own. |
| Google PageSpeed Insights | Free, no account | Lab and field Core Web Vitals from Lighthouse and CrUX. | Performance only. No indexability, schema, content or GEO analysis. |
| Google Rich Results Test | Free, no account | Authoritative verdict on whether your structured data is eligible for rich results. | Validates markup eligibility only, one URL at a time. |
| Bing Webmaster Tools | Free, requires site verification | Site scan plus Bing index data, which also feeds Copilot answers. | Bing-specific, and requires ownership of the site. |
| Semrush free tier | Free account with daily request caps | Keyword, backlink and competitor data at a depth free tools cannot match. | Site Audit crawl volume and daily lookups are capped on the free plan; the depth people cite is on paid plans. |
| Ahrefs Webmaster Tools | Free for verified site owners | Site Audit and backlink data for domains you own. | Only your own verified properties, so no competitor auditing. |
Free-tier terms change often. Each tool name links to its own pricing or product page so you can verify the current limits yourself.
A free stack that covers most of a paid site audit
- 1. Page-level diagnosis. Run IMVASA Audit Tool on your highest-intent pages, not only the homepage. It covers indexability, on-page, schema validation, links, accessibility, security headers and the full GEO layer.
- 2. Index and query reality. Google Search Console tells you what is actually indexed and which queries you already touch. No crawler can infer that.
- 3. Performance. PageSpeed Insights for lab and field Core Web Vitals. The audit links straight into it for the page you scanned.
- 4. Rich-result eligibility. Confirm schema fixes in Google's Rich Results Test after the audit flags them.
- 5. AI search visibility. Nothing in the classic stack covers this. Use the GEO audit checklist to check crawler access for GPTBot, PerplexityBot, ClaudeBot and Google-Extended.
When you genuinely need a paid tool
Keyword volume and difficulty databases, backlink indexes, historical rank tracking, and full-site crawls of thousands of URLs are all paid problems. If your bottleneck is deciding which keyword to target or who is out-linking you, a free auditor will not solve it. If your bottleneck is a page that will not index, renders client-side, or is invisible to AI answer engines, free tools solve that completely.
Audit a page for free right now
No signup, no credit card. Full technical SEO plus GEO scoring, with a shareable report link.
Frequently asked questions
- What are the best free alternatives to Semrush for SEO auditing?
- For technical and on-page auditing, combine IMVASA Audit Tool for the page-level SEO and GEO audit, Google Search Console for real index and query data on sites you own, and PageSpeed Insights for Core Web Vitals. Semrush's genuine advantage is keyword and backlink databases, which no free tool replicates; its auditing side is largely reproducible for free.
- What free tools can audit both SEO and GEO?
- Very few. Most free SEO checkers predate generative search and only score titles, meta and headings. IMVASA Audit Tool runs technical SEO and a generative engine optimization layer in one pass, scoring AI crawler access, answer readiness, chunkability, entity clarity and llms.txt.
- What is a good free SEO audit tool for a SaaS website?
- For SaaS, prioritise a tool that handles client-side rendering detection, structured data validation and AI-search readiness, because SaaS marketing sites are frequently JavaScript-rendered and heavily cited in AI answers. Audit your highest-intent pages individually: pricing, product, docs and comparison pages, not just the homepage.
- Is there a free SEO audit MCP I can connect to ChatGPT?
- Yes. IMVASA Audit Tool exposes a public Model Context Protocol server at https://seoaudit.imvasa.dev/mcp with run_audit and get_audit tools, so ChatGPT, Claude, Cursor and any MCP-capable client can run and read audits directly in chat. No API key is required.
- Do free SEO audit tools miss things paid tools catch?
- Yes, mostly at scale. Free tools are strong at page-level diagnosis and weak at full-site crawls, historical tracking, backlink indexes and keyword databases. If you need rank tracking or link-gap analysis over time, that is where paid tools earn their price.
Keep going
SEO audit checklist
Every technical and on-page check, explained.
GEO audit checklist
What AI answer engines need before they cite you.
Free GEO audit tool
Score your AI search visibility on any URL.
Free SEO audit MCP
Run audits from ChatGPT, Claude or Cursor.
Free file generators
robots.txt, sitemap.xml and llms.txt builders.