We tested the free SEO audit tools worth your time, on real sites. Here is what each one actually checks, where it is genuinely free, and the limits to know before you rely on it. No fluff, no affiliate-driven rankings.
Instant, free, no account needed - we check your homepage on the spot.
Every tool here is genuinely usable for free, not a 7-day trial that locks behind a card. We grouped them by the job they do, because "best" depends entirely on what you are trying to find. The honest truth: you will use a few of these together, not just one.
Free, and non-negotiable. It shows how Google actually sees your site: which pages are indexed, coverage and indexing errors, Core Web Vitals at scale, manual actions, and the queries you rank for. It is reactive (it reports what Google already crawled) and it will not crawl your site on demand, so pair it with a crawler. Best for: indexing status and real Google data. Limit: no on-demand crawl, data is delayed.
Free Core Web Vitals and Lighthouse performance scoring for any URL, using both lab and real-user (CrUX) data. The definitive free source for LCP, INP and CLS. Best for: performance on a per-page basis. Limit: one URL at a time, no site-wide view.
Validates your structured data against what Google can actually use for rich results. Free and authoritative for schema. Best for: confirming structured data is valid. Limit: single URL, schema only.
The classic desktop crawler, free up to 500 URLs. Deeply configurable and trusted by professionals. The free cap is fine for small sites; beyond it you need the annual licence, and very large crawls need local RAM and a capable machine. Best for: granular desktop crawling of small sites. Limit: 500-URL free cap, desktop install, no built-in history. See Screaming Frog alternatives if the cap or the install is a problem.
A web-based technical crawler with a free first full-site audit and no URL cap on the free tier. It runs 180+ technical checks (broken links, redirects, canonicals, hreflang, structured data, sitemaps, meta, indexability) plus real PageSpeed, and tracks health run-over-run so you can prove what you fixed. After the free audit it is $9 to $49 one-time, not a subscription. Best for: affordable, repeatable site-wide audits with history, nothing to install. Limit: focused on technical SEO, not a keyword or backlink suite. (Full disclosure: this is our tool. We have tried to describe it as plainly as the others.)Run a free audit.
Web-based auditors with free single-page reports and limited free crawls. Handy for a quick overview, though the free tier is usually capped to a few checks or pages per day before prompting an upgrade. Best for: a quick single-page snapshot. Limit: small daily free caps.
When you already know the issue you are chasing, a focused checker is faster than a full crawl. These Kalenux checkers are free with no signup for a single page, and free for your whole site after a free account.
Find broken internal and outbound links, redirect chains, and broken redirects, with the source page for each. Check broken links.
Validate international SEO: missing reciprocal tags, language mismatches, broken hreflang URLs and missing self-references. Check hreflang online.
Check titles, meta descriptions and Open Graph tags for length, duplication and missing values. Check meta tags.
Confirm a page is actually indexable: noindex, robots, canonical and status problems that quietly keep pages out of Google. Check indexability.
Validate your sitemap exists, parses, lists live canonical URLs, and is declared in robots.txt. Validate your sitemap.
A practical order that gets you a thorough audit without paying for anything:
Check the Pages report for indexing errors and the Core Web Vitals report for site-wide performance problems Google has already found.
Use a crawler to find what Search Console cannot: broken links, redirect chains, duplicate or missing titles and descriptions, canonical conflicts, and orphan pages. This is where most fixable issues hide. Read our 20-point technical SEO checklist for what to look for.
Run your most important templates (home, a product or post, a category) through PageSpeed Insights to see LCP, INP and CLS with real-user data.
Fix issues at the template or content level so one change clears many pages, then re-crawl to confirm. Technical SEO is iterative, so track health over time rather than auditing once.
There is no single winner, because each free tool covers a slice of the work. Search Console and PageSpeed Insights are the essential free baseline and you should have both regardless of what else you use. For a site-wide crawl, Screaming Frog is free to 500 URLs and Kalenux gives a free first full-site audit with no URL cap on the free tier. For a one-off question, a focused checker aimed at the exact issue is faster than either.
In practice most people end up running two or three of these together: Search Console for what Google has already seen, a crawler for what it has not, and a focused checker when they are chasing one specific fault.
For most small and medium sites, free coverage is genuinely sufficient. Free tools reliably surface the high-impact technical issues: broken links, indexability mistakes, canonical conflicts, missing or duplicated metadata, and slow Core Web Vitals. A combination of them adds up to a thorough technical audit without any spend at all.
You move to a paid tier for a narrower set of reasons: crawling thousands of pages regularly, scheduled monitoring, tracking health over time, auditing many client sites, or adding keyword and backlink data. That last one is a different job from technical auditing and needs a different class of tool.
Instant single-page checks are free with no account, and your first full-site audit is free after signup. Beyond that it is credit-based at $9 to $49 one-time, with no subscription and credits that never expire. It stays a focused technical-audit tool rather than a keyword or backlink suite.
Run an instant homepage check above, or sign up for a free full-site audit across 180+ technical checks plus PageSpeed.
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