A site audit tool sends a crawler through your pages and hands back a list of what’s broken. Three of the most popular ones did that to the same small website on the same day, and they disagreed on almost everything except the date. Here’s how each audit started, how far it crawled, what it flagged first, and which one you should run before the others.
Why We Ran Three Site Audit Tools on One Website
On October 21, 2026, we ran Semrush, SE Ranking and Ubersuggest against one site, and they crawled 100, 1,000 and 150 pages before stopping, per our test log. Same site, same day, default settings. The page caps alone changed what each tool could find.
Feature lists make these tools look alike. That’s not how you’ll meet them. You’ll meet them through a setup screen, a crawl limit and a score, and those three things decide whether the audit is useful to you this week.
So why these three? Each one sells a crawler-based audit inside an all-in-one SEO suite, and each let us start without a card. Mangools, the fourth suite we test, has no crawler audit at all, so it gets its own short section near the end.
This page stays on the audit itself: setup, crawl caps, issue lists, schedules and crawler settings. If you want the wider question of what an SEO checkup tells you, including authority scores and traffic estimates, our article on how four checkers scored the same website covers it.
Key Takeaways
Semrush’s documentation caps a free account at 100 audited pages per month (Semrush Site Audit), and that’s exactly where our free audit stopped. Ubersuggest’s free plan went a little further and SE Ranking’s no-card trial went much further. For a small site, start with the free Semrush audit; for a bigger one, SE Ranking’s trial covers far more pages before you pay.
Quick Verdict: Which Site Audit Tool to Run First
The free Semrush audit is the one to run first on a small site: in our test it returned a Site Health score of 89%, 97 errors and a ranked issue list from 100 pages, at no cost. SE Ranking is the pick when you need more pages, and Ubersuggest is a quick second opinion on on-page basics.
| If you need… | Run this | What our test showed |
|---|---|---|
| A free audit you can keep using | Semrush (free account) | 100 of 100 pages, Site Health 89%, 97 errors, 159 warnings |
| The most pages before you pay | SE Ranking (14-day trial, no card) | 1,000 pages crawled, Health Score 94, 2,230 issues |
| A quick on-page check | Ubersuggest (free plan) | 150 pages, On-Page SEO Score 90, 70 SEO issues |
| A check of AI crawler access | Semrush (free account) | AI Search Health 95%, Blocked from AI Search panel |
| A crawler from Mangools | None available | SiteProfiler shows domain metrics only |
Want to start one right now? These are the three official entry points:
- Semrush: the Site Audit feature page. Semrush says its lists of issues “are ranked by severity.”
- SE Ranking: the Website Audit page, which offers a 14-day trial with “no credit card needed.”
- Ubersuggest: the Site Audit page. In our test, the audit ran from a new project.
Is one audit enough? For most small sites, yes. Pick one tool as your scoreboard and re-run it after each round of fixes. If you’re still choosing a whole SEO suite rather than one crawler, our comparison of four whole SEO suites on one site weighs keyword data, backlinks and prices too.
How We Tested: Three Crawls of One Site on One Day
We ran all three audits on October 21, 2026, from one work account with Google sign-in, with every crawler setting left at its default and no card entered anywhere. Semrush and Ubersuggest ran on their free plans. SE Ranking has no free plan, so we used its 14-day trial, which asked for no card.
The test site is a small marketing site our team runs. It’s young, it has few links, and it has the rough edges most small sites have. That makes it a fair stand-in if you’re a blogger, a freelancer or a small business.
Here’s what we did not do. We didn’t fix anything between audits, open issue detail views, turn on JavaScript rendering, change crawl sources or start a paid plan. Every number below was copied from the screen, and we kept masked screenshots of each one.
Why keep the defaults? Because that’s the audit most people get. A tool’s defaults show what it thinks a beginner needs, and they’re what decides your first impression.
A note on money: Indie Stack Lab may add affiliate links to some tools later. When a link is an affiliate link, it is labeled. That did not change what we tested or what we wrote down.
Starting an Audit: Three Different Setups
Semrush took one button press, SE Ranking started its audit on its own when we created a project, and Ubersuggest walked us through five setup steps first; Ubersuggest’s audit page says a crawl takes about 10 minutes on average, per our test log. The paths differ more than the results do.
Semrush: Start SEO Audit and accept the defaults
In Semrush we opened Site Audit, pressed “Start SEO Audit,” accepted the setup screen as it was and pressed “Start audit.” The setup showed “Limit per audit 100 pages” and “Schedule: Weekly, Every Friday.” The audit finished in a few minutes.
Before that, though, sign-up ends on a plan page offering a Pro+ trial at “$299/mo … 7 days free,” and the free path is the smaller “Skip trial” button. Semrush’s documentation adds that your first project configures and launches Site Audit automatically, while later projects need a manual setup (Semrush). Our full settings walkthrough of a free Semrush audit covers every optional step of that wizard.
SE Ranking: the audit starts with the project
SE Ranking never asked us to start anything. We entered the site, changed the location from Taiwan (the default for us) to the United States, and added one tracking keyword. The project setup wouldn’t launch until we also entered at least one AI prompt. Then a notice appeared: “Audit Completed! … Health Score: 94.”
SE Ranking’s help center describes the same flow: you can choose to launch Website Audit automatically when you create a project, watch its progress in real time, and get notified in your inbox when it’s done (SE Ranking Help Center). It also offers a stand-alone audit that doesn’t need a project.
Ubersuggest: five steps before the crawl
Ubersuggest asked the most of us. After “Add Project” and “Start Analysis,” setup ran through segmentation, a business summary, competitors, AI prompts and keywords, plus an “experts help” pop-up. We skipped the optional steps.
Here’s the catch. Ubersuggest set the project’s language and location to Chinese and Taiwan based on where we connected from, and wrote the business summary in Chinese. The audit itself still ran, but if you set up a project from outside your target market, check those two fields first.
Which setup is best? If you want zero decisions, SE Ranking. If you want to see the settings before the crawl, Semrush. Most of Ubersuggest’s extra steps are about keywords, competitors and AI prompts rather than the crawl.
Page Caps: 100, 150 and 1,000 of 5,000 Pages
The free Semrush audit stopped at 100 of 100 pages, Ubersuggest’s free plan stopped at 150 with an upgrade prompt, and SE Ranking’s trial crawled 1,000 pages out of a 5,000-page trial allowance, per our test log. The cap decides which part of your site you see.
Each tool shows its cap differently:
- Semrush printed “Limit per audit 100 pages” on the setup screen and “Pages crawled 100/100” on the results.
- Ubersuggest said “We found more than 150 pages on your website… Upgrade,” with 150 pages crawled: 150 successful, 0 redirected, 0 broken and 0 blocked.
- SE Ranking showed “Account limit 1,000/5,000” on the audit and “Pages audited: 1000 / 5000” on the billing page.
What the paid tiers allow
What happens when you pay? The vendors publish these audit limits:
| Tool | Free or trial cap | Paid audit limits on the vendor’s own page |
|---|---|---|
| Semrush | 100 pages per month and per audit, 1 audit at a time | Pro 20,000 pages per audit and 100,000 per month; Business 100,000 per audit and 1,000,000 per month |
| SE Ranking | No free plan; our trial showed 5,000 audited pages | Core: 250k pages per month in audit; Growth: 2M pages per month |
| Ubersuggest | 150 pages per audit cycle | 1,000, 5,000 or 10,000 pages per weekly crawl, by tier |
Sources: Semrush Site Audit limits, SE Ranking subscription page, Ubersuggest pricing.
Semrush adds that leftover pages “do not roll over month to month” and that limits reset “on the 1st day of every month.” SE Ranking’s Core plan listed $103.20/month billed annually, or $129.00 month to month. Ubersuggest’s pricing page showed a lifetime-access countdown banner instead of one fixed plan price, so check it on the day you buy. For the plan details, see what SE Ranking’s Core and Growth tiers allow, Ubersuggest’s paid tiers and lifetime offers and how Semrush’s toolkit tiers map to its prices.
Spending a small crawl budget well
With 100 pages, which pages get crawled matters. Semrush’s default crawl source follows links “starting from the homepage,” which it warns “finds the pages most accessible from your homepage, which aren’t always your most important ones” (Semrush). Its Import URLs from file option lets you “check specific pages and conserve crawl budget.”
Count your pages before you pick a tool. A 60-page blog fits inside every cap here. A shop with 800 product pages gets a sample from the free plans and a full crawl only from SE Ranking’s trial.
Health Scores: 89%, 90 and 94, and Why They Don’t Compare
Our site scored 89% Site Health in Semrush, 90 On-Page SEO Score in Ubersuggest and 94 Health Score in SE Ranking, per our test log, and each number comes from a different formula. Close scores, very different inputs.
| Tool | Score on our site | Label shown | Pages behind it |
|---|---|---|---|
| Semrush | Site Health 89% | “Top-10% websites” benchmark at 92% | 100 |
| Ubersuggest | On-Page SEO Score 90 | “High” | 150 |
| SE Ranking | Health Score 94 | “Excellent” (recommended 90+) | 1,000 |
Semrush says its score “is based on the number of your total errors and total warnings” and that it “doesn’t depend on the number of pages crawled on the site” (Semrush). SE Ranking weighs each category, each priority and “the share of detected pages affected by the issue” (SE Ranking blog). Ubersuggest’s site audit guide explains individual checks rather than the score, so read its issue list before the number.
So is 94 better than 89%? No. They’re different rulers. What surprised us was how little the scores said about the work ahead: the 89% site still had broken internal links on 93 of its 100 crawled pages. Track one tool’s score over time, never one tool against another. The formula details and the full score-by-score breakdown are in our article on how four checkers scored the same website.
Errors, Warnings and Notices Side by Side
Semrush found 97 errors and 159 warnings, Ubersuggest found 70 SEO issues, and SE Ranking found 2,230 issues split into 6 errors, 29 warnings and 2,195 notices, per our test log. The totals look wildly different. The severity systems explain most of it.
| Tool | Severity levels | Our totals |
|---|---|---|
| Semrush | Errors, warnings, notices | 97 errors, 159 warnings |
| SE Ranking | Errors, warnings, notices | 6 errors, 29 warnings, 2,195 notices |
| Ubersuggest | One SEO issues list | 70 SEO issues |
Do notices count toward the score? Not in Semrush, which says notices “don’t impact your overall site health score” (Semrush). SE Ranking does fold priority into its score, but says “More critical problems have more influence on the final score than minor issues” (SE Ranking blog). That’s how a site with 2,230 issues can still score 94.
SE Ranking weighs categories, not only issues
SE Ranking’s Website Audit 2.0 also gives each category its own weight. Its blog lists three examples: Localization rose from 2% to 7%, Redirects from 3% to 5%, and the new Crawling & Indexing category got 20% (SE Ranking blog). The same update moved some checks between levels. Canonical chain went from warning to error, while Description missing went from error to warning.
Why does that matter to you? Because the same problem can be an error in one tool and a warning in another. Don’t compare “errors” across tools. Compare each tool’s error list with its own previous crawl.
Hiding issues changes the score
Semrush lets you hide or exclude checks, and it says hidden and excluded issues “will no longer affect your Site Health” (Semrush). That’s useful for checks that don’t apply to your site. It’s also an easy way to raise a number without fixing anything, so write down why you hid each one.
The Top Issues Each Tool Put First
Semrush put broken internal links first, on 93 pages, while Ubersuggest led with 36 poorly formatted URLs, per our test log. Same site, different first job.
| Tool | Top issues on our site |
|---|---|
| Semrush | Broken internal links (93 pages), low text to HTML ratio (89), low word count (36), content not optimized for AI Search (4), 4xx errors (1) |
| Ubersuggest | Poorly formatted URL (36 pages), title too short (18), low word count (6) |
| SE Ranking | Our log kept the totals only: 6 errors, 29 warnings, 2,195 notices |
Why didn’t they agree? They crawled different page sets with different rules. Ubersuggest counted 0 broken pages, while Semrush counted broken links on pages. A broken link inside a menu or footer appears on nearly every page, and one template fix could clear the whole row. We didn’t open the detail lists, so that’s the first thing we’d check next.
Low word count showed up in both tools, on 36 pages in Semrush and 6 in Ubersuggest. Ubersuggest says it “flags pages with fewer than 200 words as having a low word count,” and that pages like “Contact Us” or “About” often have low word counts, which usually won’t matter if those pages aren’t meant to rank (Ubersuggest Help Center). Should you pad those pages? Usually not.
Our results also fit a wider pattern. Ahrefs looked at 1,002,165 domains in 2023 and found 3XX redirects on 95.2% of sites and missing or empty meta descriptions on 72.9% (Ahrefs). Its author writes that most sites use redirects and “it’s not usually anything to worry about.” So the most common issue on a list isn’t automatically the most urgent one.
AI Search Checks Inside a Site Audit
Semrush was the only one of the three that scored AI search readiness inside the audit: our site got 95% AI Search Health, marked beta, with 4 pages flagged as “Content not optimized for AI Search,” per our test log. SE Ranking and Ubersuggest put their AI features in tracking, not in the crawler.
Semrush calls the score “a score that reflects how optimized your website is for AI search” and builds it from AI search checks, AI bot access in robots.txt and technical readiness such as “schema markup, crawlable navigation, internal links, llms.txt” (Semrush AI Search Health). Next to the score, our Blocked from AI Search panel listed ChatGPT-User, OAI-SearchBot, Googlebot and Google-Extended. We didn’t open its detail view.
What about the other two? SE Ranking’s project page showed widgets for AI Overview, AI Mode, ChatGPT, Gemini and Perplexity, but they appeared after we launched keyword and prompt tracking, not inside the audit report. Ubersuggest’s project setup offered an AI prompt step, which we skipped. Neither showed an AI score inside the audit itself.
Does an AI readiness score tell you whether ChatGPT cites you? No. It tells you whether AI crawlers can reach and read your pages. For mentions and citations, look at trackers that measure AI answer mentions.
Scheduling and JavaScript Rendering Settings
All three crawlers defaulted to a weekly rhythm: Semrush scheduled “Weekly, Every Friday,” SE Ranking set its next audit for Oct 28, 2026, and Ubersuggest says free users get “a detailed weekly report,” per our test log and Ubersuggest’s help center. Rendering is where they split.
| Setting | Semrush | SE Ranking | Ubersuggest |
|---|---|---|---|
| Default schedule we saw | Weekly, every Friday | Next update Oct 28, 2026 | Weekly report (help center) |
| Schedule options | Weekly on any day, daily, once | Weekly or monthly, time set in GMT | Weekly crawls on every paid tier |
| Re-run by hand | Any time | “Restart audit” button | Not for free users |
| JavaScript rendering | Guru or Business toolkit only | Off in our audit; switch in Parser Settings | Audits HTML pages only |
Sources: Semrush configuring Site Audit, SE Ranking Website Audit, Ubersuggest free-user limits, Ubersuggest Site Audit Guide.
The weekly default on a free budget
Here’s the catch with Semrush’s free plan. The audit re-runs weekly by default, but the budget is 100 pages per month. Our first audit used all 100. By Semrush’s own limits, the scheduled re-runs later that month have nothing left to spend. Switch the schedule to “Once” and run it by hand at the start of each month.
Ubersuggest is stricter in a different way: “Recrawling on demand is not permitted for free users” (Ubersuggest Help Center). So after you fix something, you wait for the next weekly crawl.
Does JavaScript rendering matter for your site?
SE Ranking explains that “Without JS rendering, auditing tools miss content, links, and interactive elements,” and that rendering makes the scan take longer (SE Ranking blog). Semrush says enabling it “might affect the Health Score” because the audit can “check more content” and find more problems (Semrush).
Is your site built on a JavaScript framework? If yes, an HTML-only crawl may miss much of each page, so use a tool and plan that can render. If it’s plain HTML, like most small blogs, the default is usually fine.
Crawler Access: Bots, robots.txt and Firewalls
A crawl only sees what the site lets it reach: Ubersuggest says firewalls or services like Cloudflare can mistake its crawlers for scraping, and recommends adding its IPs as exceptions (Ubersuggest Help Center). Our 150-page Ubersuggest crawl counted 0 blocked pages, and Semrush counted 1.
Each tool crawls as a different bot:
- Semrush uses SiteAuditBot (Mobile) by default, with SiteAuditBot (Desktop) and OpenAI-Search as options. Its crawl delay defaults to Minimum, about 1 second between pages (Semrush).
- SE Ranking says “Our crawler always follows the instructions specified in the robots.txt file” and identifies itself as “SEBot-WA” (SE Ranking Help Center). Its IP addresses can be whitelisted on Cloudflare.
- Ubersuggest checks the HTTPS version first, audits HTML pages only, and stops at internal links marked nofollow. If your main URL uses www and the non-www version doesn’t redirect, Ubersuggest says the crawl won’t run.
Why should a small site care? Because a “clean” audit can mean a healthy site or a crawler that got stopped early. If your report shows far fewer pages than you have, check your firewall, your robots.txt and your redirects before you celebrate.
Mangools and Screaming Frog: Where They Fit
Mangools has no crawler-based audit at all: when our task list called for one, the closest tool was SiteProfiler, which showed Domain Authority 3, Page Authority 26, Citation Flow 21 and Trust Flow 19 for our site, per our test log. Mangools describes SiteProfiler as checking authority “with the well-known SEO metrics by Moz and Majestic” (Mangools SiteProfiler).
So is SiteProfiler an audit? No. It’s useful context, but it won’t list a broken link or a missing title. If you use Mangools for keywords, pair it with a free crawler from one of the other tools. Our page on what SiteProfiler and the other Mangools tools showed has the rest of those results.
Screaming Frog, the desktop option
Screaming Frog SEO Spider is a different kind of site audit tool: a desktop crawler for Windows, macOS and Linux. Its pricing page says the software is free, and that a paid license lifts the 500-URL limit and opens the advanced features (Screaming Frog pricing). We haven’t tested it.
The free version caps each crawl at 500 URLs and restricts the crawl configuration, saving crawls, JavaScript rendering and API integrations (Screaming Frog SEO Spider). Licenses run for one year. The price shown to us was in British pounds, so check the price in your own currency at checkout.
Ahrefs Free for sites you own
Ahrefs is the other free option worth knowing. Its Site Audit page says the tool is “Free for websites with verified ownership,” with up to 5K pages a month (Ahrefs Site Audit). We haven’t tested it either. For the rest of its plans, see what Ahrefs Free and the paid Ahrefs plans include.
Which Site Audit Tool Fits Which Site
The best site audit tool depends on your page count more than on features: in our test, a 100-page free cap covered a first pass of a small site, while only SE Ranking’s trial went past 1,000 pages, per our test log. Start from your site, not from a ranking.
Here’s how we’d sort readers:
- Bloggers and solo creators: run the free Semrush audit once a month, set to “Once,” and fix the error with the highest page count first.
- Small businesses with a few key pages: point Semrush at those pages with a URL file so the free 100 pages cover what customers see.
- Shops and larger sites: use SE Ranking’s 14-day trial for one full crawl, then decide whether a paid plan is worth it. Our page on everything else the SE Ranking trial did on our site covers the rest of that trial.
- Freelancers and agencies: one free audit per month won’t stretch across several client sites. Look at client and project limits in agency SEO tools before you pick a plan.
- Anyone who wants a second opinion: run Ubersuggest’s free audit for on-page basics like titles and URLs. The rest of our Ubersuggest free-plan results on the same site show where its daily limits bite.
Do you need more than one crawler? Most small sites don’t. One audit tool plus Google’s own data is enough. Our guide on using Search Console’s own data alongside an audit explains that part, and our comparison of free-plan limits across four SEO suites shows what else each free plan includes. New to all of this? Start with a simple routine for acting on SEO tool reports.
Before your next audit, write down three numbers: your page count, your tool’s page cap and your last score. If the first is bigger than the second, you’re auditing a sample. If the third moved, check which issue moved it.
References
- Semrush Knowledge Base: How does Site Audit work?
- Semrush Knowledge Base: Configuring Site Audit
- Semrush Knowledge Base: How is Site Health Score calculated in the Site Audit tool?
- Semrush Knowledge Base: Reviewing Your Site Audit Issues
- Semrush Knowledge Base: AI Search Health in Site Audit
- Semrush: Site Audit features
- SE Ranking: Website Audit
- SE Ranking: Subscription plans
- SE Ranking Help Center: How to use Website Audit
- SE Ranking blog: New Website Audit, Health Score and JavaScript Rendering
- Ubersuggest: Site Audit
- Ubersuggest Help Center: Ubersuggest’s Site Audit Guide
- Ubersuggest Help Center: Site Audit Limits for Free Users
- Ubersuggest: Pricing
- Ahrefs: We Studied Over 1 Million Domains to Find the Most Common Technical SEO Issues
- Ahrefs: Site Audit
- Screaming Frog: SEO Spider
- Screaming Frog: SEO Spider pricing
- Mangools: SiteProfiler