Semrush Site Audit Guide: Technical SEO and Health Walkthrough

Maintaining strong organic search rankings requires constant vigilance over technical architecture, indexing directives, page speed metrics, and internal link distribution. Even minor CMS template adjustments or plugin conflicts can inadvertently trigger canonical loops, break crawl paths, or deploy accidental noindex directives across core commercial landing pages.

The Semrush Site Audit tool is an enterprise-grade cloud crawler engineered to scan websites for over 140 technical and on-page SEO issues. By organizing complex crawl diagnostics into an actionable Site Health score, thematic category reports, and prioritized severity queues, Semrush allows digital marketers, webmasters, and developers to pinpoint and fix backend defects quickly. This guide covers project configuration, crawl scoping, thematic report analysis, AI search bot accessibility, and automated remediation workflows.

Why Deploy Semrush Site Audit for Technical SEO?

While local desktop crawlers consume significant hardware memory and require manual file management, Semrush executes its crawls on dedicated cloud servers. This cloud setup provides distinct operational advantages:

• Automated Recurring Monitoring: Schedule recurring daily or weekly audits that automatically detect broken links, status code drops, and metadata anomalies right after new site deployments.
• Thematic Diagnostic Reports: Breaks down complex technical data into dedicated analytical dashboards: Crawlability, HTTPS, Core Web Vitals, Internal Linking, Markups, and International SEO.
• AI Crawler Accessibility Auditing: Checks robots.txt and server configurations against real-time AI search bots and retrieval crawlers, such as OAI-SearchBot, Claude-SearchBot, and PerplexityBot.
• Task Management Integration: Direct export paths to tools like Trello, Zapier, and Jira allow technical teams to assign discovered issues straight to development backlogs without leaving the platform.

Understanding the Semrush Site Health Score

Upon completing an audit, the main dashboard displays an overall Site Health score ranging from 0% to 100%. This metric represents the proportion of crawled internal pages that are completely free of technical errors, weighted against the overall volume and severity of detected defects.

Semrush organizes all discovered technical defects into three distinct severity tiers:

Step 1: Project Setup and Crawl Scope Configuration

Setting up an audit project correctly prevents crawl budget waste and avoids generating misleading alerts on secondary assets:

1. Define the Domain Scope:

   Enter your primary root domain. Choose whether to crawl the entire domain including subdomains, or restrict the audit to a specific directory path (such as /blog/ or an e-commerce catalog directory like /shop/).

2. Select the Crawl Source:

   Choose how the crawler discovers your URLs:

   • Website (Breadth-First): Starts at the homepage and follows internal hyperlinks naturally through the site architecture.
   • Sitemap by URL: Crawls exclusively through URLs listed in an official XML sitemap feed, ensuring indexable canonical assets take priority.
   • Robots.txt Sitemap: Detects and follows the sitemap path declared within your robots.txt file automatically.
   • Import URLs from File: Upload a dedicated CSV or TXT file of specific URLs to run a targeted migration or post-remediation audit.
3. Configure the Crawler User-Agent:

   Choose between SiteAuditBot (Mobile) and SiteAuditBot (Desktop). Because Google operates under mobile-first indexing, selecting the mobile user-agent ensures the crawl evaluates the identical responsive viewport and DOM structure parsed by Googlebot.

4. Set Crawl Throttling (Speed):

   Adjust the crawl speed to match your hosting environment. On high-performance enterprise hosting, set 5 to 10 requests per second. On shared or staging servers, choose 1 request per second to prevent 429 Too Many Requests errors or server resource exhaustion.

Step 2: Analyzing the Core Thematic Reports

Rather than working solely from an unfiltered list of hundreds of errors, use Semrush's dedicated thematic dashboards to resolve issues systematically:

1. Crawlability Report

The Crawlability dashboard highlights everything that affects how efficiently search engine bots traverse your architecture:

• Crawl Depth Graph: Visualizes how many clicks it takes to reach pages from the homepage. Ensure critical commercial pages and service hubs sit within three clicks (Depth 1 to 3).
• HTTP Status Codes: Categorizes server responses into 2xx (Success), 3xx (Redirects), 4xx (Client Errors), and 5xx (Server Errors).
• Robots.txt and Noindex Blocks: Lists pages blocked by robots directives or non-indexable meta tags, allowing you to catch accidental indexing blocks on valuable pages.

2. HTTPS Implementation Report

Security protocol inconsistencies can trigger browser security warnings and create duplicate content variants. This report verifies:

• Mixed content errors where an HTTPS page loads unsecure HTTP images, scripts, or stylesheets.
• Server redirection protocol to confirm HTTP URLs redirect to their primary HTTPS equivalent via clean 301 headers.
• SSL/TLS certificate expiration dates, domain name mismatches, and legacy security protocols (e.g., TLS 1.0 or 1.1).

3. Core Web Vitals and Performance Report

Fast page load times and visual stability are essential for both organic search ranking and conversion rates. Powered by Google Lighthouse, this report flags:

• Largest Contentful Paint (LCP): Identifies heavy hero photography, unoptimized fonts, and render-blocking scripts that delay primary content rendering past 2.5 seconds.
• Cumulative Layout Shift (CLS): Uncovers unreserved image containers, dynamic ad banners, or late-loading web fonts that cause page elements to jump.
• Technical Asset Optimization: Flags unminified JavaScript and CSS files, uncompressed image payloads, and missing browser caching headers.

4. Internal Linking Report

This report evaluates internal link distribution across your site hierarchy:

• Internal Link Distribution (LinkRank): Maps how internal PageRank passes through your site, showing which pages hold the highest internal authority.
• Orphan Pages: Surfaces pages present in your XML sitemap that receive zero internal links from anywhere across the live navigation or editorial body copy.
• Broken Inlinks & Excessive Outlinks: Highlights internal anchor tags pointing to 404 pages or pages with more than 100 outgoing links that dilute PageRank flow.

5. Markups (Structured Data) Report

Structured data allows search engines to understand page entities and display rich snippets in search results:

• Summarizes total pages containing Schema.org markup (JSON-LD, Microdata, or RDFa).
• Validates entities (such as Product, Article, Organization, and BreadcrumbList) against Google Rich Results standards.
• Flags missing mandatory properties and syntax errors that disqualify pages from rich snippets.

6. International SEO (Hreflang) Report

For multi-lingual and multi-regional domains, managing hreflang tags is often error-prone. This report catches:

• Missing self-referencing and reciprocal return tags between language pairs.
• Invalid ISO language and country codes.
• Hreflang links that point to redirected (3xx), broken (4xx), or non-canonical URLs.

Step 3: Auditing AI Search Bot Accessibility

Modern technical audits must ensure that content is crawlable by generative search engines and retrieval-augmented generation (RAG) models. In the Overview and Crawlability reports, inspect bot access rules:

• Review Search Retrieval Crawlers: Confirm your robots.txt does not disallow search retrieval bots like OAI-SearchBot (ChatGPT Search), PerplexityBot, or Claude-SearchBot if your goal is to appear in generative search citations.
• Differentiate Training vs. Search Crawlers: If your organization chooses to block AI model training while allowing AI search discovery, verify that training bots (e.g., GPTBot, Google-Extended, ClaudeBot) are handled with separate, deliberate directives in your robots file.

Step 4: Prioritizing Fixes and Managing Developer Workflows

Executing an audit effectively requires translating raw technical findings into organized tasks:

1. Filter the Issues Tab by Impact:

   Navigate to the Issues tab and select the Errors filter. Focus first on sitewide template flaws (such as broken canonical tags or missing H1s across product templates) where a single code update resolves hundreds of warnings simultaneously.

2. Use Tooltips for Remediation Context:

   Click the Why and how to fix it link next to any detected issue. Semrush provides an explanation of why search engines care about the flaw, along with direct code examples for development teams.

3. Assign Tasks to Project Boards:

   Click the task icon next to any error row to create a task in the built-in Semrush CRM or export issues directly to Trello, Jira, or CSV for tracking.

Step 5: Comparing Audits to Validate Technical Fixes

After your development team deploys code updates to staging or production, confirm resolution:

1. Click Re-run audit in the top-right corner of the Site Audit project dashboard.
2. Navigate to the Compare Crawls tab once processing finishes.
3. Review the comparison matrix to verify that the count of red Errors has decreased, resolved issues are marked green, and no regressions have surfaced.
4. Check the Progress tab to track your Site Health score over time as you complete sprints.

Semrush Technical Audit Checklist

Use the checklist below to verify that your technical audit covers all essential areas:

Maintain Long-Term Site Health

A technical audit should be an ongoing maintenance standard rather than an isolated fix. By scheduling recurring cloud crawls, configuring mobile user-agents, tracking your Site Health score, and systematically working through the thematic dashboards in Semrush, you keep your site architecture clean, accessible to modern search engines, and optimized for long-term organic visibility.