What’s the best free SEO audit tool right now

General
1

I’m trying to improve my site’s rankings and need a reliable free SEO audit tool that can scan for technical issues, broken links, and on-page problems. I’ve tried a few random tools from Google, but most have strict limits or miss important errors. What free SEO audit tools are you actually using that give solid, actionable insights without forcing an upgrade right away

2

Short answer from a cheapskate SEO nerd: use a combo, not one tool.

If you want a single best free audit tool to start with:

  1. Ahrefs Webmaster Tools (AWT)

    • Needs site verification.
    • Full site crawl, technical issues, internal links, broken links, redirects, Core Web Vitals, basic content issues.
    • Good “Errors / Warnings / Notices” breakdown.
    • Decent for ongoing monitoring, not only a one time scan.

  2. Screaming Frog SEO Spider (free desktop, up to 500 URLs)

    • Gold standard for technical checks.
    • Finds:
      • Broken links (4xx, 5xx)
      • Redirect chains
      • Missing / duplicate titles and meta descriptions
      • H1 issues
      • Canonicals
      • Noindex / nofollow
    • Best combo is: crawl with Screaming Frog, then export and filter in Excel or Sheets.

  3. For on page and content:

    • Ahrefs Webmaster Tools → Page explorer.
    • Also use Google Search Console for:
      • Indexing issues
      • Mobile usability
      • Performance by query and URL.

Simple setup that works for most small sites:

Step 1: Connect site to

  • Google Search Console
  • Ahrefs Webmaster Tools

Step 2: Run AWT Site Audit weekly

  • Fix 4xx/5xx first.
  • Fix redirect chains.
  • Fix title / meta / H1 issues on pages with impressions in Search Console.

Step 3: Run Screaming Frog once a month

  • Crawl mode: Spider.
  • Set user agent to Googlebot.
  • Export “Response Codes” and filter “Client Error 4xx” and “Redirection 3xx”.
  • Export “Page Titles” and “Meta Description” reports to spot duplicates and missing fields.

Step 4: Free extras

  • PageSpeed Insights for a few key URLs for Core Web Vitals.
  • Bing Webmaster Tools for extra crawl and index data.

If you want one button, web only:

  • Ahrefs Webmaster Tools beats most free web scans from random sites.
  • Most other “free audit” pages limit you to 100 URLs and spam you with sales emails.

If you share your site size and CMS, people can give more specific tool setups.

3

If you want one “best” free audit tool, you’re gonna be disappointed. There isn’t one. There’s “tolerable combo of free stuff” vs “pay a subscription and stop suffering.”

@espritlibre already nailed a really solid stack, so I’ll avoid rehashing Screaming Frog + Ahrefs Webmaster Tools and all the step‑by‑step. Instead, here’s a different angle that works well if you want to stay free and still get actual value:

1. Best single free crawler if you hate installing stuff: Sitebulb Cloud (trial) or SEO PowerSuite Website Auditor (free tier)

  • Website Auditor (desktop) lets you crawl a decent chunk of URLs for free, and gives you:
    • Technical issues: status codes, redirects, canonical, hreflang, robots, noindex
    • On‑page stuff: missing titles, duplicate content, thin content
  • It’s less strict than a lot of “free scan” SaaS tools that choke at 100 URLs and start begging for your credit card.
  • UX isn’t pretty, but if you care more about data than shiny dashboards, it works.

2. For broken links specifically: use a dedicated link checker
Sometimes a full SEO suite is overkill when you just want broken links. Use:

  • Check My Links Chrome extension (for single pages)
  • Xenu Link Sleuth (ancient, ugly, still weirdly effective if you’re on Windows)
    They’ll hammer through pages fast and spot every 404, even on bigger sites.

3. On‑page + content issues without hitting SaaS paywalls
Instead of a “magic” audit tool, combine:

  • Google Search Console:
    • Coverage report: indexing issues
    • Performance: which pages get impressions but low CTR
  • Then use a free on‑page grader like Seobility or Seobility-type tools on a few key URLs instead of the whole site.
    • Yes, they limit scans, but used sparingly on your top pages, they’re fine.

4. Site speed & Core Web Vitals without going down a rabbit hole

  • PageSpeed Insights for 3–5 key URLs
  • Ignore the obsession with chasing a 100 score and focus on:
    • LCP, CLS, TBT
    • Big layout shifts, huge unoptimized images, blocking JS

5. If you really want one primary “SEO audit” interface
I’d actually pick Seobility or Sitechecker free tier over most random “SEO audit” generators.

  • They’ll crawl more than 100 URLs on the free plan (within reason)
  • Give clear issue lists: titles, meta, headings, status codes, redirects
  • Less thorough than the Ahrefs/Screaming Frog combo, but simpler if you’re just starting and don’t want 20 reports and CSVs.

Minor disagreement with @espritlibre: if your site is tiny (like under 100 pages) and you’re not super technical, spinning up Screaming Frog and exporting to Excel can be complete overkill. In that case:

  • Pick one crawler (Website Auditor, Seobility, or Sitechecker free)
  • Add Google Search Console
  • Fix what shows up repeatedly: 4xx errors, missing / duplicated titles, noindex mistakes, bad internal links

If you share roughly:

  • how many URLs
  • your CMS (WordPress, Shopify, custom, etc.)
    people can suggest a tighter combo instead of the “here’s every tool on earth” approach.