The best SEO audit tools are Google Search Console for index data, a desktop crawler such as Screaming Frog or Sitebulb for deep technical checks, and an all-in-one suite such as Semrush or Ahrefs if you also need backlink and keyword data. Most sites need one free Google tool plus one crawler. Nobody needs five.
tl;dr
- 1Start with Google Search Console and Bing Webmaster Tools. They are free and show what the search engines actually see.
- 2For a crawl, Screaming Frog is the standard; Sitebulb explains issues more clearly; Ahrefs Webmaster Tools is free for sites you own.
- 3All-in-one suites are worth it only if you will use their keyword and backlink data too.
- 4No tool prioritizes for you. A health score is a count of issues, not a plan.
This roundup supports our complete SEO audit guide. Every free limit and price below was checked on the vendor's own site in October 2026; plans change, so confirm before you buy.
SEO audit tools compared
This table compares the main SEO site audit tools by what they do best and what they cost to start.
| Tool | Type | Best for | Free option (as of Oct 2026) |
|---|---|---|---|
| Google Search Console | Search engine data | Index coverage, real clicks, Core Web Vitals | Free |
| Bing Webmaster Tools | Search engine data + Site Scan crawler | Bing index data, a free cloud crawl | Free |
| Screaming Frog SEO Spider | Desktop crawler | Deep technical crawls, custom extraction | Free up to 500 URLs; paid licence $279 per year |
| Sitebulb | Desktop or cloud crawler | Clear issue explanations and prioritized hints | 14-day free trial |
| Ahrefs Webmaster Tools | Cloud crawler + backlinks | Free audits of sites you own | Free, 5,000 crawl credits per month per project |
| Semrush Site Audit | Cloud crawler in a suite | Teams already on Semrush | Free account: 100 pages per month |
| PageSpeed Insights | Performance test | Core Web Vitals by URL | Free |
Free SEO audit tools from the search engines
The free search engine tools are the starting point for any SEO website audit, because they report what Google and Bing actually did, not what a third-party crawler guesses.
Google Search Console shows which pages are indexed, why others are not, which canonical Google picked, which queries earn clicks, and how pages perform on Core Web Vitals. The URL Inspection tool inside it shows how Google rendered a specific page and lets you request reindexing. No other tool has this data.
Bing Webmaster Tools gives the same kind of index and query data for Bing, and includes Site Scan, an on-demand crawler that flags common technical issues. Bing sets each site's scan quota automatically. Bing data matters more than it used to, because several AI assistants draw on Bing's index.
PageSpeed Insights combines real-user Core Web Vitals from the Chrome UX Report with a Lighthouse lab test. Use it to diagnose slow templates after Search Console tells you which ones are slow.
Best crawlers for technical SEO audits
A crawler is the core of any technical audit, covered step by step in our technical SEO audit guide. It visits every URL and records status codes, titles, canonicals, directives and links.
Screaming Frog SEO Spider is the most widely used desktop crawler. According to its pricing page, the free version crawls up to 500 URLs and a paid licence costs $279 per year with no crawl limit beyond your machine's memory and storage. It renders JavaScript, connects to Search Console and analytics, and supports custom extraction. The trade-off is a steep learning curve: it shows you everything and explains little.
Sitebulb is a crawler built around explanations. Each issue comes with a description of why it matters and how to fix it, which makes it easier to hand findings to clients or developers. Its pricing page lists a Lite plan at 10,000 URLs per audit and a Pro plan at 500,000 URLs per audit, plus a 14-day free trial equivalent to Pro.
Enterprise cloud crawlers such as Lumar and Botify suit sites with millions of URLs, scheduled crawls and log file analysis across teams. Most sites under 100,000 URLs do not need them.
All-in-one suites with site audit tools
All-in-one suites include a site audit crawler alongside keyword research, rank tracking and backlink data. They make sense if you will use the whole suite.
Ahrefs Webmaster Tools is the free entry point to Ahrefs. Per Ahrefs' own page, it audits verified sites for 170+ technical and on-page issues with 5,000 crawl credits per month per project, and shows backlink data for your own sites. Auditing competitors' sites requires a paid Ahrefs plan.
Semrush Site Audit runs in the cloud and groups issues into errors, warnings and notices. Semrush's knowledge base lists 100 pages per month for accounts without an SEO Toolkit plan, and 100,000 pages per month (20,000 per audit) on Pro. It is a good fit for teams already paying for Semrush.
How to choose an SEO audit tool
Choose an SEO audit tool by site size, budget and who will read the output.
| Situation | Recommended setup |
|---|---|
| Small site, no budget | Search Console + Screaming Frog free (500 URLs) or Ahrefs Webmaster Tools |
| Freelancer or in-house SEO | Search Console + Screaming Frog paid |
| Agency handing reports to clients | Search Console + Sitebulb, for its explanations |
| Team already on a suite | Search Console + the suite's site audit |
| Site with millions of URLs | Search Console + enterprise cloud crawler + log analysis |
For quick single-page checks, our free On-Page SEO Checker tests indexing, titles, headings and links with no signup. The free SEO audit tool guide explains how to combine it with speed and link checks.
Our view: the tool matters less than the person reading the output. Every tool here will report hundreds of "issues" on a healthy site. The skill is deciding which five matter.
Frequently asked questions
What is the best free SEO audit tool?
Google Search Console is the best free SEO audit tool, because it shows what Google has actually indexed and why other pages were left out. For crawling, Screaming Frog's free version handles up to 500 URLs, and Ahrefs Webmaster Tools audits sites you own for free. Combining Search Console with one free crawler covers a complete audit of most small sites.
Is Screaming Frog better than Semrush for site audits?
Screaming Frog is better for deep, configurable technical crawls, custom extraction and JavaScript rendering checks, and it costs less if you only need crawling. Semrush Site Audit is better if your team already uses Semrush for keywords and backlinks and wants scheduled cloud crawls with simpler reports. Many SEO teams use Screaming Frog for diagnosis and a suite for monitoring.
Do I need a paid SEO site audit tool?
You do not need a paid SEO site audit tool for a site under 500 pages: Search Console, Bing Webmaster Tools, PageSpeed Insights and a free crawler tier cover it. Paid tools become worth it for larger sites, regular client reporting, scheduled monitoring, or when you need backlink and competitor data that free tools restrict to your own sites.
Can SEO audit tools check AI search visibility?
Standard SEO audit tools check the foundations AI search depends on, such as crawlability, indexing and rendering, but most do not measure whether ChatGPT, Perplexity or Google AI Overviews mention your brand. As of October 2026, that needs a separate AI visibility tracker or manual testing of real buyer questions across each engine.
How accurate are SEO audit tool health scores?
SEO audit tool health scores are consistent but not meaningful on their own. Each tool weighs issues differently, so the same site can score very differently across tools. A score counts issues; it does not know which pages earn revenue. Use scores to track progress over time within one tool, and use the individual findings to decide what to fix.
If you would rather have the audit run and prioritized for you, AEO GEO Labs offers fixed-fee SEO audits that include AI search visibility. See our services.