Your website might be losing organic traffic right now — not because of bad content or weak backlinks, but because of a technical issue Google can’t overlook: a broken redirect chain, duplicate title tags, slow-loading pages, or a crawl budget problem you don’t even know exists.
Site auditing is the unsexy but essential foundation of SEO. Before keyword rankings, before link building, before content strategy — your site needs to be technically sound. Semrush’s Site Audit tool is one of the most widely used solutions for this job. This guide breaks down exactly what it does, how to use it, and whether it’s the right choice for your needs.
What Is the Semrush Site Audit Tool?
Semrush Site Audit is a crawler-based technical SEO analysis tool built into the Semrush platform. It systematically crawls your website the same way search engine bots do — following links, indexing pages, and checking each one against a set of over 140 technical parameters.
The result is a “Site Health Score” (expressed as a percentage) that reflects the overall technical condition of your site, alongside a categorized list of issues organized by severity. The tool doesn’t just surface problems — it explains what each issue is, why it matters, and how to fix it.
Key Features of Semrush Site Audit
Crawlability and Indexability Issues
Semrush checks whether search engines can actually access and index your pages. This includes crawl errors, blocked pages (in robots.txt or meta noindex tags), broken internal and external links, redirect chains, and canonical tag problems.
Core Web Vitals Data
Semrush integrates Google’s Core Web Vitals metrics into its audit, pulling data on Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and Interaction to Next Paint (INP). These page experience signals are ranking factors.
HTTPS and Security Checks
The tool verifies SSL certificate validity, checks for mixed content issues, and flags security configuration problems that could trigger browser warnings or erode trust signals with Google.
Internal Linking Analysis
Semrush maps your internal link structure and identifies problems: broken internal links, orphaned pages (pages with no internal links), pages with excessive outgoing links, and internal link chains.
Duplicate Content Detection
The audit identifies duplicate and near-duplicate content at the page level — including duplicate title tags, meta descriptions, H1 tags, and body content.
Page Speed Issues
Semrush flags render-blocking resources, uncompressed images, unminified JavaScript and CSS, and server response time problems.
Structured Data Validation
Semrush checks for schema markup errors and incomplete structured data that can prevent rich results in Google Search.
How to Run a Site Audit in Semrush (Step-by-Step)
Step 1: Create or select a project — Log into Semrush and navigate to the Projects dashboard. Create a new project for your domain.
Step 2: Open Site Audit from the project — Inside your project, click “Site Audit” in the left-side navigation.
Step 3: Configure crawl settings — Set the number of pages to crawl per audit. Choose whether to crawl by site crawl, sitemap, or both. Using your XML sitemap as a guide is recommended.
Step 4: Set crawl source and user agent — Semrush lets you specify whether the crawl simulates Googlebot, Semrush’s own bot, or a standard browser.
Step 5: Start the crawl — Depending on your site size and plan limits, the crawl may take anywhere from a few minutes to a few hours.
Step 6: Review the Overview report — Once complete, Semrush shows your Site Health Score (aim for 80%+) and a breakdown of issues by category. Start with “Errors” before “Warnings” and “Notices.”
Step 7: Prioritize and action fixes — Click into any issue category to see affected pages, understand the problem, and follow Semrush’s “How to fix it” guidance.
How to Read Semrush Site Audit Results
Site Health Score: A percentage (0–100%) representing the ratio of healthy pages vs. pages with issues. Scores above 80% are generally acceptable; above 90% is strong.
Errors: The most serious issues — broken pages (4xx errors), pages blocked from crawling incorrectly, significant redirect chains, missing HTTPS.
Warnings: Issues that should be addressed but aren’t immediately critical — slow page load times, suboptimal title tag lengths, non-optimized images.
Notices: Informational items that may or may not require action depending on context.
Semrush Site Audit Limits by Plan
| Plan | Pages per Month | Projects |
|---|---|---|
| Free | Up to 100 pages | 1 |
| Pro ($139.95/mo) | 100,000 pages | 5 |
| Guru ($249.95/mo) | 300,000 pages | 15 |
| Business ($499.95/mo) | 1,000,000 pages | 40 |
Important notes: “Pages per month” refers to the total crawl budget across all your projects. Scheduling recurring audits (weekly/monthly) counts against this total. For most small businesses with sites under 5,000 pages, the Pro plan is more than adequate.
Semrush Site Audit vs Competitors
| Tool | Checks (approx.) | Monthly Cost | Best For |
|---|---|---|---|
| Semrush Site Audit | 140+ parameters | From $139.95/mo (Pro) | All-around technical SEO with ecosystem integration |
| Screaming Frog | 120+ parameters | £259/yr (~$21/mo) | Deep, custom technical auditing by SEO specialists |
| Ahrefs Site Audit | 130+ parameters | From $129/mo (Lite) | Teams already using Ahrefs for backlinks/keywords |
| Google Search Console | Basic crawl errors | Free | First-line monitoring of indexing issues |
| Allable | AI-powered audit | Visit allable.ai | SMBs and solopreneurs wanting actionable audit results without a technical SEO background |
Screaming Frog is often preferred by senior SEO specialists who want maximum customization. Its annual fee is significantly lower, but requires technical knowledge to extract and interpret results.
Allable takes a different approach: rather than a raw crawl report to decode, Allable’s AI-powered site audit surfaces the most important issues in plain language with clear prioritization. For small business owners who need to understand and fix SEO problems without hiring a technical SEO consultant, this is a materially more accessible experience.
Is Semrush Site Audit Worth It?
When Semrush Site Audit is excellent:
- You’re already using Semrush for keyword research and competitive analysis — the audit integrates natively
- You manage a website with thousands of pages that need regular health monitoring
- You want a single platform where audit findings connect directly to rank tracking and backlink data
- Your team includes someone with SEO knowledge who can interpret technical audit outputs
When it might be overkill:
- You have a small site (under 50 pages) where free tools like Google Search Console catch the key issues
- You’re a non-technical business owner who needs actionable guidance rather than a raw crawl report
Frequently Asked Questions
Is Semrush site audit free?
Semrush offers a limited free version that crawls up to 100 pages. Full functionality requires a paid Semrush plan starting at $139.95/month.
How accurate is Semrush site audit?
Semrush Site Audit is highly accurate for the issues it checks. The key limitation is interpretation: the tool flags issues without always knowing whether they’re intentional. Some SEO judgment is required to distinguish true problems from expected configurations.
How often should I run a Semrush site audit?
For active websites undergoing development or regular content updates, running a weekly automated audit is ideal. For stable sites, monthly audits are typically sufficient.
What does Semrush site audit check?
140+ parameters across six main categories: crawlability and indexability, site performance and Core Web Vitals, HTTPS and security, internal linking structure, duplicate content, and structured data/markup. Each issue is categorized by severity with actionable fix guidance.
Can Semrush audit my entire website?
Yes, provided your site is within your plan’s crawl limit. Pro plan users can crawl up to 100,000 pages per month across their projects. Guru allows 300,000 pages/month, and Business allows 1 million pages/month.