SEO Audit Tools: Crawlers, Browser Extensions and Cloud Auditors, and the Findings None of Them Can Judge

Every audit tool is a crawler with a rulebook stapled to it

Strip away the dashboards and an SEO audit tool does two things. First it fetches pages the way a search engine bot does, following links from one URL to the next and recording what comes back: status codes, titles, headings, canonical tags, redirects, image sizes, load times. Then it runs that record against a list of rules a vendor wrote, and turns every broken rule into an issue with a color.

The first half is close to objective. The second half is opinion, which is why two tools can audit one site on one morning and disagree about how sick it is. The tools come in four shapes; most sites need two.

If you are new to the vocabulary these tools throw at you, read our guide to technical SEO first. The SEO tools hub shows where an audit tool sits in a full stack at each budget.

Screaming Frog and Sitebulb: a full crawl from your own desk

Screaming Frog's SEO Spider is the desktop crawler we reach for first. Its product page lists what it catches: broken links and server errors, redirect chains and loops, missing or duplicate titles and descriptions, exact duplicate pages found with an md5 check, URLs blocked by robots.txt, and images that are too large or lack alt text. The free version crawls up to 500 URLs. Screaming Frog says crawl configuration, saving crawls and advanced features such as JavaScript rendering are also restricted without a license.

As of October 2026 a license costs $279 a year per user on Screaming Frog's pricing page, dropping to $265 each for 5 to 9 licenses, $249 for 10 to 19 and $235 for 20 or more. The paid version's ceiling depends on your memory and storage. A 120-page local site fits in the free version; for a store with 8,000 product URLs, the license is the cheapest serious audit there is.

Sitebulb is the gentler alternative: also on the desktop, but it explains each finding in plain prose where Screaming Frog shows a spreadsheet. Its pricing page lists Lite at 10,000 URLs per audit and Pro at 500,000, with a 14-day Pro trial and no card required. Dollar prices load by script and did not show to our check, so check current pricing; the FAQ puts Sitebulb Cloud from £95 a month.

SEOquake, Lighthouse and the one-page checkup

SEOquake is a free browser extension from Semrush. Its Chrome Web Store listing, updated October 15, 2026, shows about a million users and a 3.5 rating from about 2,600 ratings. It audits the page you are on for issues such as robots directives, hreflang, alt text and structured data, and its SERP overlay prints Semrush metrics under each Google result. One oddity: seoquake.com now redirects to a page checker on Backlinko, a Semrush property, with three free checks a day.

Lighthouse is Google's open-source page auditor, with checks for performance, accessibility, SEO and more. It runs in Chrome DevTools, from the command line or through PageSpeed Insights. Its SEO checks are basic and honest about it: a missing meta description, a page blocked from indexing, an invalid robots.txt, a bad canonical or hreflang, link text that says nothing, tap targets too small for a thumb.

• Use a page checker to confirm a fix on one URL or study a competitor's page, never to judge a whole site.
• Read keyword density as description, not a target. SEOquake reports which words a page repeats most. Google does not ask for a ratio, and its spam policies treat stuffing as a problem; see keyword stuffing.
• Treat Lighthouse's SEO score as a checklist count. Google's documentation says each SEO audit carries equal weight in the score, apart from a manual structured data check, and that Lighthouse does not evaluate the quality of your description.

Many extensions ask permission to read the pages you visit, so install few and remove the ones you stopped using. Our guide to SEO Chrome extensions covers the others worth having and the privacy questions to ask before you click Add to Chrome.

Cloud auditors and suite audits, priced as of October 2026

Past a few hundred thousand URLs, a laptop crawl becomes an overnight job that crashes at 3 a.m. Cloud auditors crawl on a schedule and keep the history. Most businesses never need one. Every figure below comes from the vendor's own pricing or help pages in October 2026, and DataCram is not a partner, affiliate or reseller of any of them.

Two notes on the free rows. Ahrefs Free only audits sites you verify, so it is no help for studying a competitor. And Semrush's free allowance covers a hundred pages, which is a full audit for many local sites and a sample for everyone else. Plan by plan, our Semrush pricing breakdown and Ahrefs review cover what the suites add on top.

What Google and Bing will tell you about your own crawl, free

A crawler shows what it found. Search Console shows what Google found. Its Page indexing report lists the pages Google left out and why, and URL Inspection shows how Google last saw one page. Search Console's help center adds a line every audit report should print at the top: "Don't expect every URL on your site to be indexed." Google expects to index the canonical pages, not every filtered, paginated or duplicate address.

Bing Webmaster Tools has its own on-demand crawler, Site Scan, which Bing introduced in 2020 as an audit tool that checks a site for common technical SEO issues. It is part of the free account. Our guide to free SEO tools covers both consoles in more depth, and the Search Console guide walks through the indexing reports.

Our own free checks sit beside these. The website audit reviews speed signals, search basics, mobile, security and content and sends the findings as a PDF with fixes. The website health check runs 25 checks on one URL in about ten seconds.

The findings a crawler cannot weigh

An audit tool counts well and judges badly. It knows a title is 71 characters long. It does not know whether the title makes a homeowner in Schertz want to click.

Google's own documentation undercuts several common audit warnings. Tools flag thin word counts; Google's guidance on helpful content asks whether you are writing to a particular word count and answers its own question: "No, we don't." Tools flag long meta descriptions; Google says there is no limit on their length and that it truncates snippets to fit the screen. Tools flag pages missing from the index; Google says not to expect every URL there. None of that makes the warnings useless. It makes them questions, not orders.

An audit tool can count every heading on the page and still miss that the page is about the wrong thing.

The same goes for the questions Google's guidance asks writers to put to themselves: does the page offer original information, reporting or analysis, and does it show real experience? Our page on E-E-A-T explains why no crawler can score those, and why Google says E-E-A-T itself is not a specific ranking factor.

Sorting a 4,000-issue report in one afternoon

The report arrives sorted by the tool's severity, which is the tool's opinion. Sort it again by damage to the business. This is the order we work in on client sites; it is our practice, not a rule anyone publishes.

1. 1

   First, anything that hides pages from Google

   Noindex on pages that should rank, robots.txt rules blocking folders, server errors on key templates. Confirm each in Search Console first.

2. 2

   Second, broken paths to the pages that make money

   Internal links that 404, and redirect chains on service, product and contact pages. Point each link straight at the final URL. Our guides to redirects and fixing broken links cover the details.

3. 3

   Third, duplicates and canonicals

   Two URLs serving one page, or a canonical tag pointing somewhere odd. The canonical tags guide shows how to read them.

4. 4

   Fourth, titles and descriptions on the top 20 pages

   Fix the pages that earn impressions first. A duplicate title on a 2019 tag archive can wait. The meta tags guide covers what to write.

5. 5

   Fifth, speed on the templates customers use

   One fix to a page template repairs every page built on it. Start with the template your service or product pages share.

6. 6

   Last, decide what to ignore

   Alt text on decorative images, pages you meant to keep out of the index, character counts a few over a vendor's limit. Note why, so the next audit does not reopen the argument.

Crawl again after the fixes, then put the audit on a calendar. A quarterly crawl is part of the routine in our guide to SEO maintenance.

Which audit tool fits the site you actually have

• A local business site under 500 pages: Screaming Frog's free version once a quarter, Lighthouse for single pages, and Search Console every month. Total cost: nothing.
• A growing site of 500 to 50,000 pages: a Screaming Frog license at $279 a year, or Sitebulb if you want the findings explained. Schedule the crawl monthly.
• Anyone already paying for a suite: use the audit inside it before buying another tool. Our Ahrefs vs Semrush comparison lists each suite's audit allowance.
• A store or publisher with hundreds of thousands of URLs: a cloud crawler that keeps history and reads server logs, so you see what Googlebot visits, not only what links exist.
• A site about to be rebuilt or moved: a full crawl before launch, saved, so every old URL can be mapped to a new one. Our website migration work starts there.

The tool is the cheap part. The report it produces can take twenty hours to act on, and an audit nobody works through is a receipt, not a repair.

That is what DataCram's SEO programs do: we run the crawlers we already pay for, sort the findings by what costs you customers, fix them and report the result. Programs run month to month on a defined scope from $625 a month, and the SEO pricing page shows where most local businesses land. If you want to see your own findings first, the free website audit is the place to start.