An e-commerce website can have great products and fair prices and still struggle in search. In my experience running an online store and working in SEO, the cause is usually technical: pages search engines cannot crawl, product pages competing with each other, or a slow site visitors leave before it loads. A technical SEO audit finds those problems before they cost you sales.

I run Synex Technologies, an e-commerce store built on OpenCart, and I have spent years working on SEO and digital operations. This is the checklist I use when I audit an online store, and it works on OpenCart, WooCommerce, Shopify or a custom platform.

1. Crawlability: Can Search Engines Reach Your Pages?

If a crawler cannot reach a page, that page cannot rank, no matter how good its content is. Start every audit here.

Check your robots.txt file

Read your robots.txt file line by line. Make sure it does not block your product pages, category pages or images; a staging rule or a plugin setting can easily block a whole section of a live store by accident. At the same time, use robots.txt to keep crawlers away from pages that should never appear in search, such as the cart, checkout and account pages.

Review your XML sitemap

Your sitemap should list every page you want indexed and nothing you do not. Submit it in Google Search Console, check for errors, and remove any broken links, redirected pages or pages blocked by robots.txt.

Fix crawl errors

Check the crawl errors reported in Search Console. Broken links, server errors and redirect chains waste crawl budget and frustrate visitors, so fix the errors affecting real pages first.

2. Indexation: Are the Right Pages in the Index?

Crawlable is not the same as indexed. Compare the pages you want in search results with the pages Google has actually indexed. Many stores accidentally index filtered category pages, sorting parameters and internal search results. These thin, near-duplicate pages dilute your site and confuse search engines about which page should rank, so use noindex or canonical tags to keep them out. Also check that your main category pages and best-selling products are indexed.

3. Site Structure and URLs

Aim for a logical hierarchy: home page, then categories, then subcategories, then products. No important page should sit more than three or four clicks from the home page.

• Use short, readable URLs that include the product or category name.
• Avoid URLs full of parameters, session IDs or meaningless numbers.
• Make sure every product and category page is reachable through the navigation or internal links, not only through search.

4. Product and Category Page Optimisation

Product and category pages are where e-commerce SEO is won or lost. Each one needs to be useful and distinct.

Write unique product descriptions

Never copy the manufacturer's description word for word, and never reuse the same description across similar products. Explain what the product does, who it suits and what makes it different, and present the key specifications in a clear table or list.

Optimise titles and meta descriptions

Every product and category page needs a unique title tag and meta description. Include the main keyword naturally and give the searcher a reason to click. Keep titles around 50 to 60 characters and meta descriptions around 140 to 160 characters.

Use headings properly

Each page should have one H1, usually the product or category name. Use H2 headings for the main sections and H3 headings for subsections, so the page is easy to scan for readers and search engines alike.

5. Duplicate Content

Duplicate content is one of the most common problems on e-commerce sites. The same product can appear under several categories, with different sorting options, or with only a colour or size difference, leaving search engines unsure which version to show.

• Use canonical tags to point duplicate or near-duplicate URLs to the preferred version.
• Decide on one preferred URL format and redirect the alternatives to it.
• For products that differ only by a small detail, consider one page with options rather than a separate page for every variant.
• Check for duplicate title tags and meta descriptions and rewrite them.

6. Internal Linking

Internal links guide visitors and pass authority between pages. Link from category pages to their products and back again, add a related products section on product pages, and link from blog posts and buying guides to the relevant products. Use descriptive anchor text, not generic phrases like "click here".

7. Core Web Vitals and Performance

Speed matters for both rankings and sales. A slow product page loses visitors, especially on mobile, where most e-commerce browsing now happens. Test your key pages with PageSpeed Insights, focusing on the three Core Web Vitals: how quickly the main content appears, how stable the layout is, and how quickly the page responds.

• Compress and resize product images, and load images below the fold only when the visitor scrolls to them.
• Reduce the number of scripts and stylesheets loading on each page.
• Enable compression and browser caching on the server.
• Keep product pages simple so the product, price and buy button appear quickly.

8. Mobile Friendliness

Most shoppers will visit your store on a phone. Check your site on a real mobile device, not just by resizing a desktop browser. Buttons should be easy to tap, text readable without zooming, and the checkout smooth on a small screen. Use the mobile usability reports in Search Console to catch problem pages.

9. Structured Data (Schema Markup)

Structured data helps search engines understand your pages and can earn richer results in search, such as prices and availability. For e-commerce, product schema is the priority. Make sure the markup matches what visitors see on the page, and validate it with Google's Rich Results Test. Never add markup for information that is not on the page, and never invent ratings or reviews.

Frequently Asked Questions

How often should I audit my e-commerce site?

Do a full technical audit at least twice a year, and after any major change such as a redesign. Check Search Console errors and page speed every month.

Which SEO tool do I need for an audit?

Google Search Console and PageSpeed Insights are free and cover the essentials. A crawling tool is useful for larger stores because it finds broken links, duplicate titles and redirect problems across thousands of pages quickly.

What is the most common technical SEO problem on e-commerce sites?

In my experience, duplicate content from filtered and sorted category pages is the most common issue, followed by missing or duplicate meta descriptions. Both are fixable with canonical tags and a routine for writing unique titles and descriptions.

Should I fix everything at once?

No. Start with the issues that block crawling and indexing, then fix the pages that bring the most traffic and revenue. A prioritised list is more useful than a long report nobody acts on.

Putting the Audit into Practice

A technical SEO audit is not a one-time project. It is a routine that keeps a store healthy as products are added and the platform is updated. Work through this checklist in order, fix the blocking issues first, and record what you changed.