If you're like most humans, the word "audit" gives you an instant twinge of anxiety. But if you're an SEO professional (and thus not like most humans), it might fill your head with grand visions of actionable marketing insights.

Digital marketers depend on tools that generate these insights, so we can learn what's bringing traffic to a website, why content is plummeting on the SERP, and how copy on a page can be improved.

I've used plenty of SEO audit tools in my career, and to help you pick the right one for your needs, I spent even more time testing the top options.

Ranging from free auditing apps to enterprise-level marketing suites, these products will help SEO pros at any level diagnose and improve site performance.

The best SEO audit tools

• SEOptimer for SMBs

• Small SEO Tools for free auditing

• Screaming Frog for a free version of a premium product

• SE Ranking for value

• Semrush for an audit tool from a premium SEO suite

• Ahrefs for technical auditing

• Clearscope for on-page optimization

• ContentKing for real-time monitoring

What makes the best SEO audit tool?

There's a healthy bit of hair-splitting that goes on with naming SEO tool categories. SEO audit software, SEO rank trackers, keyword research tools, and more general SEO tools have a lot of crossover because the companies that do one thing well tend to do other things well, too.

That's all to say my definition might be different from yours, but here's what I was looking for in the best SEO audit tools:

• Dedicated audit features: SEO auditing could be the product's main function, or it could be a separate dashboard within a more comprehensive suite.

• Multiple SEO-related metrics: The product should report on more than one metric applicable to SEO, like page speed, traffic, user behavior, and keyword saturation.

• Scoring with actionable SEO insights: Metrics should be presentable as an exportable report (say that five times fast) and include actionable SEO insights.

• Reputable: The software's provider should be widely respected in the industry, provide transparency about its scoring methodology, and/or rely on reputable data sources like Google Search Console.

I tested each of the apps on this list, and, like a new single on "Love Island," each ticks all the boxes. I've also tested dozens of others and researched dozens more SEO tools over the past several months. So while you may disagree with my picks, I can attest that each one is a quality option that should more than meet your SEO auditing needs.

The best SEO audit tools at a glance

Best SEO audit tool for SMBs

SEOptimer (Web)

SEOptimer pros:

• Reasonably priced and feature-rich

• Over 60 independent tools for auditing, research, and generation

• White label reporting and audit tool embedding

SEOptimer cons:

• Lowest tier lacks some key features

• Lacks some of the tools you get from premium products

If your goal is to spend a lot of money on an SEO tool, there are plenty of premium options out there. But if you want a really dynamic SEO audit tool at budget pricing, SEOptimer is one of my favorites.

Like many of the premium tools, SEOptimer has the usual SEO fare, like keyword research, rank tracking, and reporting, but it's also got a nice collection of independent auditing tools like:

• Title tag checker

• Meta description checker

• SERP preview

• Website word count

• Noindex tag test

• Font size and legibility checker

Many of these are the sorts of insights you could get in a detailed SEO audit, but it's handy to have standalone modules for each one in case you just want a quick check on something like mobile responsiveness or core metrics.

Its quick audit tool gives a helpful general overview of metrics like on-page SEO, social media viability, and user-friendliness (looks like SEOptimer could use some of its own advice there). Below the score summary is a list of individual elements and recommendations for each metric, ranked by priority. 

If you want downloadable reports on your metrics, you'll have to upgrade to the (still reasonably priced) White Label tier, which also gives you access to white-label reporting in 15 languages. And with API access and an embeddable tool, SEOptimer gives even small agencies and solo consultants access to an inclusive tool they can deploy for their own clients. Is the depth of reporting and functionality quite as robust as premium tools like Ahrefs or Semrush? No. Is it surprisingly robust SMB software? Absolutely.

SEOptimer pricing: DIY SEO ($19/month), White Label ($29/month), White Label and Embedding ($59/month)

Best free SEO audit tool suite

Small SEO Tools (Web)

Small SEO Tools pros:

• Free, unlimited access to nearly 300 tools

• Wide range of SEO use cases

• Generative tools

Small SEO Tools cons:

• Very lo-fi

• No report exporting features

• Premium products have better free versions of many SEO audit tools

This category is tricky—you can get really good free SEO auditing tools from paid products, which often have free auditing tools or entirely free plans. But if you're really motivated to pick a totally free tool that blocks (almost) no features behind paywalls, Small SEO Tools is a good bet.

The only thing small about Small SEO Tools is the price tag on its nearly 300 SEO and SEO-adjacent tools. These individual apps break down into a couple dozen main categories, including:

• Text analysis

• Image editing and design

• Keywords

• Backlinks

• Website management

• Website tracking

• Proxy

• Domain

• Meta tag

Auditing tools mostly fall into the "website management" category, including options like an SEO score checker, a Google PageRank checker, a page speed tester, and a mobile-friendliness tester. 

You get the sense pretty quickly for the trade-off of all this free-ness: these are some bare-bones tools that are all function and little form. On the plus side, they're nimble and there are a lot of them, so if you're dedicated to not paying for tools within a single suite, this site has you covered. There's even an impressive array of free generative tools to help you take action on your audits. You can do things like rewrite articles, paraphrase text, proofread, create logos, and edit images with a slew of almost suspiciously specific applications.

To be clear, competing versions of most of these several hundred free tools are available elsewhere online, but what's useful about Small SEO Tools is that it crams them all into one interface. And the only things you can pay for are premium modules for plagiarism checking, image searching, paraphrasing, and image-to-text generation, so it's pretty unlikely you'll run into a paywall while you play around with these apps.

Small SEO Tools pricing: Free, with options to pay for premium tools

Best free SEO audit tool from a premium product

Screaming Frog (macOS, Windows, Linux)

Screaming Frog pros:

• Crawls up to 500 URLs in the free plan

• Easily exports to spreadsheets

• Upgrade is reasonably priced

Screaming Frog cons:

• Not very visually dynamic

• Runs on a desktop, not a browser

With its desktop-based SEO Spider tool, Screaming Frog has become a household name for SEO auditing—and its free version could be plenty for businesses and individuals on a tight marketing budget.

One of the key limitations of free trial tools is crawl budget. Websites with years of content, tons of product pages, or auto-generated pages could easily have thousands upon thousands of pages. That means the 500 URL crawl limit could indeed be pretty limiting, but that's actually pretty generous among free plans (Semrush's, for example, maxes out at 100). For smaller, newer sites, 500 should be plenty.

What you do get from free SEO Spider is the ability to analyze elements like broken links, metadata, hreflang attributes, and duplicate pages, plus sitemap generation. Structured like a spreadsheet, this lo-fi desktop software gives you an easily sortable overview of your website, so you can quickly find issues, review core vitals, and readily export findings to Excel or Google Sheets.

Screaming Frog isn't for everyone. If you like browser-based audit tools that are more interactive and play a little easier with live websites, it's probably not the vibe for you. But when it comes to reporting on essential SEO issues and metrics, this is one of the more generous free plans among the usual premium software options.

Screaming Frog pricing: Free, Paid ($259/year)

Best value SEO audit tool

SE Ranking (Web)

SE Ranking pros:

• Clean data visualizations

• Flexible audit grouping

• On-page SEO and backlink audits

SE Ranking cons:

• May hit crawl limits at lowest tier

SE Ranking has had a consistent presence on my SEO tool roundups because I'm always impressed by the bang they give you for your proverbial buck. Starting at less than half the price of premium SEO suites, it packs a veritable ton of features into its user-friendly interface, including a strong audit tool.

From the main dashboard, you can download PDF reports, connect to Looker Studio, send reports directly to partners, or generate a sitemap. These audits have many of the same metrics you'll find in just about any tool on this list, but I like SE Ranking's clean data presentation, which has a few unique callouts. The core web vitals chart is especially useful, showing a detailed breakdown of your site by user experience ratings. 

I also like the flexibility of SE Ranking's audit tool, which allows you to name individual audits, sort them into groups, hide resources, and set allowed/disallowed URLs. You can then compare audits in a dedicated comparison dashboard to see how site improvements are going over time. It even monitors page changes automatically, so you can get regular performance updates.

Beyond general SEO audits, SE Ranking includes separate tools for auditing backlinks and on-page SEO performance. Using AI, SE Rankings' on-page SEO audit shows a highly detailed breakdown of key technical and SEO elements on individual pages and suggests changes in a handy checklist widget so you can get low-performing pieces to rise in rankings.

It's worth noting that SE Rankings' pricing tiers scale by number of pages without an option for unlimited pages, so if you're auditing massive volumes of pages, you could hit your limit. But for pretty average usage, SE Ranking has the goods for a fraction of the cost of premium products.

SE Ranking pricing: Essential ($55/month), Pro ($109/month), Business ($239/month)

Best SEO audit tool from a premium SEO suite

Semrush (Web)

Semrush pros:

• Rich reporting

• Ability to compare audits and track issue resolutions

• Clean, highly responsive interface

Semrush cons:

• May be cost-prohibitive

• Free version maxes at 100 URLs

With some of the smartest, smoothest SEO tools in the game, it's probably no surprise that Semrush makes this list in some capacity. And with its lowest tier priced higher than many products' premium tiers, it's positioned for users with spacious marketing budgets.

I've always liked Semrush's interface, and its clean, responsive design extends to its audit tool. The overview dashboard gives you a really clear picture of your website's hang-ups and uniquely charts them over time. As you dig into the issues, you can follow breadcrumbs to the individual links and even get detailed explanations of what the issue type means and how you can fix it. You can even re-crawl specific pages straight from the dashboard to see if you've fixed the issue.

As you peruse tabs on the audit, you can sort link charts by things like number of issues, crawl depth, page views, and status code. Hovering over a column header shows you a pop-out description to give you insights into the metrics—like ILR, or Internal LinkRank, which Semrush describes as a measurement of "link juice" (a phrase I've always found vaguely gross for reasons I can't explain).

One of the really helpful things about this audit tool is that it allows you to measure improvement. You can compare current and past audits, review an audit stat dashboard, and even track issue types and resolutions over time on a full-size line chart.

And Semrush connects to Zapier, so you can do things like send Slack channel messages for completed audits. Here's a taste of what else Zapier can automate with Semrush.

Many of these features are available for the free version, but you'll have to pay up if you want full features or to go above the pretty confining 100 URL limit. If you're willing to pay up, in my book, Semrush's audit tool has the best combination of features, user experience, and ease of use among premium SEO suites.

Semrush pricing: Free, Pro ($129.95/month), Guru ($249.95/month), Business ($499.95/month)

Best SEO audit tool for technical auditing

Ahrefs (Web)

Ahrefs pros:

• Lots of analysis categories

• Breaks down audit by site structure

• Multiple tools for recommending site improvements

Ahrefs cons:

• User experience isn't quite as clean as some other premium tools

• May be cost-prohibitive

One of the go-to tool suites for SEO professionals, Ahrefs' site audit tool is powerful enough for marketers at every level to get highly actionable marketing insights.

Unlike less-than-premium audit tools, Ahrefs' has a pretty extensive breakdown of its analysis. You can peruse a list of issues (expandable to view deeper insights), review the crawl log, explore individual pages or links, dive into indexability factors, or spelunk into the performance metrics (ran out of verbs at the end). You can even link directly with Google tools like PageSpeed Insights and Core Web Vitals to Google-fy your analyses.

One of the more unique audit features is the ability to explore the audit by structure. This interface shows you how metrics like HTTP status code, content type, traffic, and indexability stack up on structural levels based on your site's hierarchy. This can help you potentially diagnose those hard-to-find structural issues when you can't figure out why performance is down even though you're seemingly doing everything right.

Another highlight feature is the Internal Link Opportunities application, which recommends anchor text and target URLs for pages across your whole website. Since target suggestions are based on slugs, it's not always 100% accurate—theoretically, if you run a hybrid cybersecurity/shelf-stable cooking blog, it might suggest linking anchor text on how to block spam to a recipe page on cooking with a block of Spam. But it's still incredibly useful for optimizing internal linking.

Ahrefs isn't necessarily known for being the most impressive platform out there from a UX standpoint, but the audit tool is definitely simple enough to get up and running. (Just note that the free audit tool will require website ownership verification, which can be a hassle.) I found it a little tougher to navigate than Semrush, but it's not that hard to get the hang of. Small downside for one of the best technical SEO tools out there.

Ahrefs pricing: Lite ($99/month), Standard ($199/month), Advanced ($399/month), Enterprise ($999/month)

Best SEO audit tool for on-page optimization

Clearscope (Web)

Clearscope pros:

• Detailed on-page SEO auditing

• Suggestions for keywords, questions, and citations

• Multiple keyword research and tracking tools

Clearscope cons:

• Fairly limited utility

• Premium price tag

Ok, this one's kind of a cheat. Unlike the rest of the tools on this list, which perform domain-level crawls to tell you what's going on with your website, Clearscope is strictly focused on the content of a single page.

Clearscope's primary purpose is to analyze the copy on a webpage and provide suggestions on improving its searchability. Loading up blog content like the AI-generated one in the image above, you can see metrics like how long the post should be, text readability, relevant keywords you can add to the copy, and keyword density. 

It even has a handy tab for pulling up research on the topic from around the web, showing you common questions about the target topic and webpages other posts are linking to. The outline tab is also really helpful, as it wrangles the heading structure for top-ranking posts and serves them up in a convenient list.

Beyond the on-page stuff, Clearscope also has tools for more general keyword research, position tracking, keyword discovery, and even keyword opportunities. I don't imagine there are many fuller-service SEO tools Clearscope can replace, but as a premium standalone tool, it's the gold standard for automatic on-page SEO auditing.

Clearscope pricing: Essentials ($199/month), Business (custom), Enterprise (custom)

Best SEO audit tool for real-time monitoring

ContentKing (Web)

ContentKing pros:

• Real-time 24/7 auditing

• Highly responsive, user-friendly interface

• Proprietary Importance metric

ContentKing cons:

• Pricing model is unclear

• Doesn't have as many supplemental tools as comprehensive SEO suites

ContentKing is one of the more unique SEO auditing tools on the market. If its website is to be believed, it's the only tool of its kind with real-time audit updating, meaning your dashboard shows up-to-the-minute analysis every time you look at it.

ContentKing isn't exactly a household name (at least not in the U.S.), and to be totally transparent, I'd never heard of it until I saw other SEO professionals mention it in Reddit forums (at which point I tried it out for myself). And sure, you could just re-crawl a website or webpage every time you want an update, but round-the-clock updating makes it a more complete data hub.

Like many other audit tools, ContentKing gives a detailed breakdown of site performance issues with colorful graphs, along with an overall health score (out of 1,000 for major granularity). I also like the proprietary metric Importance, which calculates a 1 to 10 score that gauges the value of a page to the site's performance using a secret recipe of metrics. This can help users prioritize pages to update. 

As a dedicated SEO audit tool, ContentKing does lack some of the deeper functionality of high-end comprehensive tools in the realms of idea generation, competitive analysis, and keyword tracking. It's really best suited as a pure auditing/performance monitoring dashboard. But it does integrate with tools like Google Analytics, Adobe Analytics, Looker Studio, and Slack, so you can really pump up the analytical jams. 

Overall, ContentKing has a really slick interface that's incredibly responsive. Hovering over issues updates the little health bar in the corner of the nav, showing how much the fix would improve site health (kind of like distributing EXP when you level up in an old-school RPG). I also like how every link, metric, or category is a clickable widget that comes with its own details, explanation, or interactive element. There's clearly a lot of intention built into the design, and it's working.

My biggest knock on ContentKing is that pricing is kind of shady—it's scaled by plan and number of pages and isn't standardized like most products. Zapier qualifies for Enterprise pricing, so I have no idea what this thing costs. (SaaSworthy reports plans start at $49 per month for up to 1,000 pages, but I can't verify this.)

ContentKing pricing: Varies

What about Google's SEO audit tools?

Since the vast majority of SEO data is connected specifically to Google Search results, the most accurate SEO data will come straight from the search-horse's mouth. In fact, many audit tools either source data from these audit tools or have optional integrations with them.

• Google Search Console: Webmaster tools for reporting on technical elements related to search performance

• Google Analytics: Provides real-time reports on key website performance metrics

• PageSpeed Insights: Analyzes website and webpage loading speeds and provides suggestions for improvement

• Looker Studio: A tool that pulls data for reporting and visualization

Technically, I could have included any of these tools in this roundup since they meet all my criteria and offer the most accurate Google traffic data available. I just didn't want half the list to be Google products, and instead, I focused on the kinds of subscription-based tools I think most people are looking for.

Make the most of your SEO audit tool

Whichever SEO tool you pick, remember that very few products out there are dedicated solely to auditing. Most are part of more general SEO suites, so it's worth considering your long-term SEO needs and whether your product of choice has other tools you'll need down the road.

It's also worth considering whether the software integrates with other apps you commonly use. If it doesn't, Zapier probably does, enabling you to build automated workflows across applications.

Related reading:

• How to use automation to keep an eye on the competition

• The best SEO content optimization tools

• A step-by-step guide to competitive market analysis

• Programmatic SEO: How to increase search traffic with no-code tools