Quality control: how to find and fix hidden errors on your website
Launching a website or starting active search engine promotion without conducting a technical audit is one of the main mistakes in digital marketing. Any efforts to buy ads or write texts will be useless if the website's shopping cart is broken, pages take 10 seconds to load, and search robots cannot index important sections due to errors in the configuration file.
Technical audit is a comprehensive analysis of the codebase, architecture, web server settings, and markup aimed at identifying errors that prevent website ranking in search engines and reduce conversions. In this guide, we have compiled a detailed step-by-step checklist to help you independently verify the quality of your resource.
Why is an audit needed and when to conduct it
Conducting a technical audit is recommended in three cases:
- Before launching a new website (to fix developer errors before they start affecting real clients).
- In case of a sharp drop in rankings in search engines or a drop in conversion rate.
- Regularly (once every six months) for system maintenance, as plugins are updated, content is added, and search engine requirements are constantly growing.
“Even a minor bug in the code, invisible to a regular user, can cost a company millions of rubles in lost profits. For example, if during a CMS update the SSL certificate broke or sending contact forms to email stopped working.”
Step 1. Loading speed and Core Web Vitals
User experience begins with speed. Use the Google PageSpeed Insights tool and check three main Core Web Vitals metrics:
- LCP (Largest Contentful Paint). The heaviest block on the first screen should render faster than 2.5 seconds. To achieve this, compress graphics, use WebP/AVIF formats, and configure preload for critical resources.
- INP (Interaction to Next Paint). Interface click response latency must be less than 200 ms. Optimize JavaScript execution and move heavy logic to the server.
- CLS (Cumulative Layout Shift). Layout must not shift during loading. Specify explicit dimensions
widthandheightfor images and ad banners.
Step 2. SEO metrics and indexing
Search engine crawlers should scan your site quickly and correctly. Check basic system files:
- robots.txt file. Ensure system folders (admin panel, cart, personal accounts) are closed from indexing via the directive
Disallow, while useful pages are accessible. Specify a correct link to the sitemap. - sitemap.xml file. The sitemap must contain only relevant URLs with a 200 OK response code. It should not contain redirects (301/302) or error pages (404). It must update automatically.
- Duplicate pages and Canonical tags. Set up the main mirror (canonical domain setup with or without www, http and https) and specify canonical URLs
<link rel="canonical" href="...">on all landing pages to avoid duplicates.
Step 3. Clean markup and microdata
Search engines and browsers find it easier to process valid code without critical syntax errors:
- Check HTML code via W3C validator. Fix unclosed tags and incorrect heading hierarchy (there must be strictly one tag on the page
<h1>). - Ensure the presence of Schema.org microdata. For commercial websites, it is critical to implement organization (`Organization`), catalog and pricing (`Product`/`Offer`), breadcrumb (`BreadcrumbList`), and quick answer (`FAQPage`) markup. It makes snippets in search results more attractive and increases CTR.
Step 4. Website security
Resource security protects you from search engine sanctions (getting blacklisted due to viruses) and leaks of users' personal data:
- SSL certificate. The site must operate strictly over the secure HTTPS protocol. Set up a 301 redirect from HTTP to HTTPS at the web server level.
- Protection against XSS and SQL injections. All feedback, search, and filtering forms must undergo strict backend validation. Implement CAPTCHA or smart slider filters to protect against spam bots.
- Data backup. Set up automated backups of the database and site files to a third-party cloud storage at least once a week.
Conclusion
A technical audit is not a one-off event, but the foundation of a healthy website. Systematically fixing minor technical errors guarantees stable resource operation under any load, increases customer loyalty through fast and convenient page operation, and paves the way for successful SEO promotion and ROI on contextual advertising.