Semrush Site Audit: Setup, Settings, What to Fix First

The Semrush Site Audit is a cloud crawler that tests your website against 140+ technical and on-page SEO checks, grades the result as a site health score, and sorts every problem into errors, warnings and notices. Configure it well (the right crawl scope, the right crawl source, JavaScript rendering where your site needs it, a weekly schedule) and it becomes a reliable early-warning system for your whole site. Configure it badly and it buries you in noise. This guide covers the setup we use on client sites at Luckywebs, what the health score actually measures, and a triage table for what to fix first, what can wait, and what to ignore.

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What does the Semrush Site Audit actually check?

The Semrush Site Audit runs more than 140 individual checks across every page it crawls, then groups the findings into three severity levels: errors (the serious problems), warnings (medium severity) and notices (informational). On top of the raw issue list, it builds thematic reports covering crawlability, HTTPS, internal linking, site performance, markup, Core Web Vitals and international SEO, each with its own sub-score. As of July 2026 there is also a newer AI Search category that checks how ready your pages are for AI-driven search results; our guide to optimising for AI Overviews covers that side in depth. The tool lives inside a Semrush project, so the audit sits alongside position tracking and backlink data for the same domain. It is a big reason Semrush earns its place in our SEO tools hub, and our full Semrush review covers every module in detail.

How do you set up a Semrush site audit?

Setting up a Semrush site audit takes about five minutes, and the choices you make here decide whether the results are useful or misleading. Create a project for your domain, open Site Audit, then work through the settings in this order:

1. Set the crawl scope. Audit the root domain by default. Untick “Crawl all subdomains” if subdomains (staging, app, blog on a subdomain) would pollute the results, or scope to a single subfolder for large sites.
2. Pick the crawl source. “Website” crawls from the homepage breadth-first, the way Googlebot discovers pages. The sitemap options audit only the URLs you say exist. You can also upload a .csv or .txt file of specific URLs.
3. Set the page limit. Cap the crawl within your plan allowance so one audit does not burn the month’s budget.
4. Choose the user agent. SemrushBot or GoogleBot, each in mobile or desktop versions. Switch to GoogleBot when a firewall blocks unfamiliar bots. There is also an OpenAI-Search user agent, useful for checking your site is crawlable by ChatGPT’s search bot.
5. Enable JavaScript rendering if your site needs it. Essential for JS-heavy builds, otherwise the crawler grades an empty shell. This sits on the higher tiers (see the FAQ below).
6. Strip URL parameters and set allow/disallow rules. Remove UTM and pagination parameters so the crawler does not count the same page five times, and exclude basket, account and search paths.
7. Schedule it. One-off, daily, or weekly on a day you choose. Weekly is right for most sites.

Run the first crawl, then triage the output. Our technical SEO audit in an hour walkthrough shows how we turn that first crawl into a prioritised fix list in a single sitting.

Which Semrush site audit settings matter most?

Most Semrush site audit settings can stay on their defaults. A handful genuinely change the quality of your results. Here is how we set them on client projects:

Setting	What it does	Our recommendation
Crawl scope	Domain, subdomain or subfolder; subdomains on or off	Root domain only, unless subdomains hold real content
Crawl source	Homepage crawl vs sitemap vs URL file	”Website” for discovery audits, sitemap for indexation checks
JavaScript rendering	Executes JS so the crawler sees rendered content	On for JS frameworks, off for server-rendered and static sites
URL parameters	Strips query strings before crawling	Strip UTM, sort and pagination parameters
Allow/disallow	Includes or excludes paths	Exclude basket, login, internal search
Crawl delay	Three speeds: minimum delay, respect robots.txt, or 1 URL per 2 seconds	Respect robots.txt; drop to the slowest speed on fragile shared hosting
Schedule	One-off, daily or weekly	Weekly, the morning of your reporting day

The crawl source choice is the one people get wrong: a sitemap-only crawl cannot find orphaned pages or broken internal links, because it never follows links at all.

What does the site health score mean?

The site health score is Semrush’s zero-to-100 summary of your audit, based on the errors and warnings found on the pages crawled. Errors carry more weight than warnings, so clearing ten errors moves the score further than clearing ten warnings, while notices have minimal effect on the number. Two details matter. First, the score does not depend on how many pages you crawl: it reflects how frequently each issue occurs, so a 500-page site and a 50,000-page site are scored on the same basis. Second, fixing every instance of one check (all broken links, say) lifts the score more than fixing single errors from several different checks, because frequency is what the calculation rewards (all per Semrush’s help centre, as of July 2026). Treat the score as a trend line for your own site, not a league table against other sites, and do not chase 100: a healthy, well-maintained site typically settles in the high 80s to low 90s with a residue of deliberate warnings left on the board.

What should you fix first in Site Audit?

The fastest way to fix Site Audit issues is to triage by consequence, not by the order Semrush lists them. Errors that block crawling, indexing or trust come first; presentation-level warnings can wait for a scheduled batch; many notices are safe to ignore once confirmed deliberate. This is the split we apply on every client audit:

Priority	Typical issue types	Why
Fix now (this week)	5xx server errors, broken internal links, redirect loops, pages wrongly noindexed or blocked in robots.txt, broken canonicals, mixed content on HTTPS pages, hreflang conflicts	These stop pages being crawled, indexed or trusted. Every day they persist costs visibility
Fix later (this month)	Redirect chains, duplicate or missing title tags and meta descriptions, missing alt attributes, slow-loading pages, thin pages you actually want to rank, orphaned pages	Real problems, but they degrade performance rather than block it. Batch them template by template
Ignore (usually)	Permanent redirect notices, nofollow on outgoing internal links, resources you blocked on purpose, crawl-depth notices on large catalogues, findings from subdomains outside your scope	Often deliberate architecture decisions. Confirm intent once, then mute the check

Work template by template rather than URL by URL: one template fix usually clears hundreds of instances at once, which is also exactly what moves the health score. The discipline pays commercially too: clean technical foundations underpinned our rebuild for law firm client RAKLaw, whose leads rose 60 percent afterwards.

Which checks are worth trusting, and which are noise?

Semrush Site Audit checks are not all equal. The structural checks are dependable because they are binary: a link either returns a 404 or it does not. The judgement-based checks need a human filter, because the tool cannot know your intent.

Worth trusting:

• Broken internal links and 4xx/5xx errors
• Redirect chains and loops
• Duplicate title tags and duplicate content across templates
• Canonical and hreflang conflicts
• Mixed content and other HTTPS issues
• Pages blocked from crawling that should not be

Treat as noise until proven otherwise:

• Low word count flags on contact, category and utility pages that were never meant to rank
• Crawl-depth warnings on big ecommerce catalogues, where depth is a product of range, not poor architecture
• Nofollow-on-internal-links notices when the nofollow is deliberate
• Title length warnings for titles a few characters over the line
• Page speed verdicts from the crawler: confirm against real field data in PageSpeed Insights before spending money on them

When a check keeps flagging something deliberate, mute it rather than letting it pad the issue count every week.

How many pages can you crawl, and how often should you run it?

Semrush meters Site Audit with a monthly page budget plus a cap per individual audit, both set by your plan. As of July 2026, Semrush’s help centre lists the limits below, though it still quotes them under the older Pro, Guru and Business toolkit names; we have mapped those onto the current lineup ourselves (all prices USD), so confirm your exact plan’s numbers on the pricing page before buying.

Plan (current lineup)	Pages per month	Pages per single audit
Free account	100	100
SEO ($139/mo, about £102) or Starter ($199/mo, about £146)	100,000	20,000
Pro+ ($299/mo, about £220)	300,000	20,000
Advanced ($549/mo, about £403)	1,000,000	100,000

For cadence: weekly scheduled crawls suit most business sites, with an extra one-off crawl after any release, migration or template change. Daily crawls only earn their keep on large sites that change constantly, and they eat budget fast. If you are unsure which tier your site needs, our Semrush pricing breakdown works through the current plans and annual discounts.

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Semrush Site Audit: frequently asked questions

Is the Semrush Site Audit free?

Partly. A free Semrush account can audit up to 100 pages per month: enough to trial the interface, not enough for monitoring. Paid plans carry a 7-day free trial (card required) as of July 2026, which covers a full audit and a re-crawl. Our Semrush free trial guide explains how to get the most from those seven days.

What is a good site health score?

There is no official pass mark. A site in the high 80s to low 90s with only deliberate notices left is in good shape. The useful comparison is your own score last month, not somebody else’s site: a falling score is an early warning.

Does the Semrush Site Audit render JavaScript?

Yes, as an optional setting, but not on every plan. As of July 2026 Semrush’s help centre states JS rendering requires a Guru or Business toolkit subscription; those are the older plan names, which on our mapping correspond to the Pro+ ($299/mo, about £220, USD) and Advanced ($549/mo, about £403) tiers of the current lineup rather than SEO or Starter. Check with Semrush before buying a plan for this feature alone. If your site is built on a JavaScript framework and rendered client-side, audit results without JS rendering will be misleading, so budget for the higher tier. Expect the health score to dip the first time you switch rendering on: the crawler suddenly sees issues it previously missed.

Can Site Audit crawl a staging or password-protected site?

Yes. The “Crawling with your credentials” setting accepts a login for password-protected environments, and a separate option bypasses robots.txt disallow rules once you have verified ownership of the site. Auditing staging before launch is one of the best uses of the tool: you fix problems before Google ever sees them.

Do Site Audit issues directly affect Google rankings?

No. The health score is Semrush’s metric, not Google’s. What affects rankings is the underlying reality the checks point at: pages that cannot be crawled, duplicate content, broken journeys. Fix issues for what they do to users and crawlers, not to make a dashboard number go up.

How does Site Audit compare with SE Ranking’s audit?

Both cover the core checks well. Semrush goes deeper on issue coverage and JS rendering; SE Ranking costs considerably less and its audit is generous at the entry tier. We compare the two platforms end to end, audits included, in our SE Ranking vs Semrush comparison.

Where should a beginner start with Semrush?

Start with one project, one weekly audit and the fix-now column of the triage table above. Our Semrush for beginners guide walks through the first month with the platform, Site Audit included.