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E-commerce duplicate content happens when the same or very similar product and category content appears at several addresses, such as filtered and sorted versions of a category, separate pages for each product variant, or supplier descriptions shared by many stores. Fixing it means deciding which address is the main version of each page, stopping search engines from crawling endless filter combinations, and making key product content your own. This guide walks through each source of duplication and its fix.
Duplicate content is not a penalty in itself, but it spreads search engines' attention across many near-identical pages instead of your best ones. If you would like help with your store's search visibility, our SEO service page explains how we work.
Where duplicates come from in stores
Most online stores create duplicates without anyone intending to.
| Source | Example | Usual fix |
|---|---|---|
| Filters and sorting | A category sorted by price or filtered by colour, each with its own address | Prevent crawling of filter combinations; point to the main category |
| Product variants | A page for each size or colour of the same product | One main product page, with a canonical tag on any variant pages |
| Several category paths | The same product reached through different categories, with different addresses | One canonical product address |
| Tracking parameters | Campaign codes added to links | Canonical tags pointing to the clean address |
| Supplier descriptions | The same manufacturer text on many stores | Write your own descriptions for key products |
| Pagination and print versions | Extra versions of the same listing | Clear canonical choices and sensible linking |
Start by listing which of these apply to your store, using a crawl of your site and the pages Google Search Console reports.
Separate currency or country versions of pages are another source to check, and our guide to multi-currency ecommerce explains how stores show and charge in several currencies.
Filter and sort URLs
Filters and sorting are useful for customers but can create very large numbers of addresses. Google's guidance on faceted navigation explains that these URLs can lead to overcrawling and slower discovery of new content, and recommends preventing them from being crawled if you do not need them indexed.
- Decide which filtered pages deserve to be found, such as a popular brand within a category. These can become proper landing pages with their own content.
- Prevent crawling of the rest, for example with robots.txt rules for filter and sort parameters, following Google's guidance.
- Keep filtered addresses out of your XML sitemap.
- Link internally to main category pages, not to filtered versions.
- Check Search Console for large numbers of filter URLs being discovered.
A common mistake and its fix
A common mistake is blocking crawling of pages that already carry a canonical or noindex tag. If crawlers cannot visit the page, they cannot see those tags. The fix is to choose one approach per type of URL, based on Google's guidance, and apply it consistently.
Product variants and canonical tags for ecommerce duplicate content
A canonical tag tells search engines which address is the main version of a page. Google's guide to consolidating duplicate URLs lists redirects and rel="canonical" link annotations as strong signals, and sitemap inclusion as a weak one. Google may still choose a different canonical if the signals conflict.
- Choose one main address for each product, usually without category paths or parameters.
- Add a canonical tag on every version of the product page pointing to that main address.
- Handle variants deliberately. Where variants share one page, use that page as the canonical. Where each variant has its own page with genuinely different content, such as distinct images and details, it may deserve its own canonical.
- Include only canonical addresses in your sitemap.
- Use the same address in internal links, menus and product feeds.
A worked example
A clothing store's shirt page can be reached through "Men > Shirts", "Sale" and a campaign link, each creating a different address. The store chooses one clean product address, adds a canonical tag pointing to it on every version, lists only that address in the sitemap and uses it in menus and emails. Search engines now see one strong page instead of three weak copies.
Supplier product descriptions
Many stores sell the same products using the manufacturer's description, so the same text appears on many websites.
Steps to make key products your own
- Prioritise products that matter most, such as best sellers and products with high margins.
- Write your own descriptions that answer customers' real questions: fit, use, compatibility and care.
- Add unique details, such as your own photos, sizing advice or comparisons with similar products.
- Use customer questions and support messages as a source of useful content.
- Keep specifications accurate, using supplier data for technical details where it is correct.
Decision criteria for which products to rewrite first
- Products that bring the most revenue or search visits.
- Products where customers often ask the same questions.
- Categories where competitors use identical supplier text.
Our guide on how to plan a product catalogue before building a store explains how to organise product data so this work is easier.
Checking the fix worked
Changes to canonicals and crawling take time to be reflected in search.
- Crawl your site again and confirm canonical tags, sitemaps and internal links point to the chosen addresses.
- Use Search Console's page indexing reports to see which duplicates Google has recognised and which canonical it chose.
- Inspect individual URLs to compare your declared canonical with Google's selected canonical.
- Watch filter URL discovery fall after crawling rules are in place.
- Track the main pages' clicks and positions over the following weeks.
Questions to ask when reviewing results
- Did Google choose the same canonical we declared for our key pages?
- Are filter and parameter URLs still being discovered in large numbers?
- Have the main category and product pages gained clicks?
If you are restructuring the whole store or moving platforms at the same time, follow our guide on how to migrate a website without losing search traffic. Travel sites face a similar problem with search result pages, covered in our guide to travel website SEO.
Recheck after any website redesign, since new templates can bring duplicates back.
Summary
- Online stores create duplicates through filters, sorting, variants, several category paths, tracking codes and supplier text.
- Follow Google's guidance to prevent crawling of filter combinations you do not need indexed.
- Choose one main address per product and signal it with redirects, canonical tags, sitemaps and internal links.
- Rewrite descriptions for your most important products and add unique details.
- Check results with a new crawl and Search Console, and give changes time to take effect.
Clean, consistent product and category pages help search engines focus on your best content. If you'd like help fixing duplicate content on your store, you can tell us about it here.
