Technical SEO for online stores

Technical SEO is the part of SEO that makes sure search engines can find your pages, read them, index them and understand them. Google processes a page in three steps: it crawls it, renders it and indexes it.

Online stores have more to keep track of than most sites. Variants, filters, sorting and pagination can create many addresses for the same products. Products are added and removed every week. And because every product page uses the same template, one error can affect thousands of pages at once.

robots.txt controls what Google may fetch. It is not a way to keep pages out of Google. Google can still index a blocked address without its content if other pages link to it. To keep a page out of the index, use noindex and let Google crawl the page so it can see it.

Your sitemap should only list the addresses you want in Google: canonical, with status 200 and without noindex. One sitemap file may hold at most 50,000 addresses or 50 MB, so large stores split it up. Google uses lastmod when the date is consistently accurate.

Open the Page indexing report in Search Console once a month. See whether important categories and products are listed as not indexed, and why.

An online store easily creates several addresses for the same content: with and without www, with tracking parameters, sort orders, or a product reachable through several categories. Tell Google which address is the right one. A redirect is the strongest signal, the canonical tag is also strong, and the sitemap is a weak signal. Google may still choose another.

Do not use robots.txt or noindex to choose the right address. Google says robots.txt should not be used for that, and noindex removes the page entirely.

Variants such as colour and size can sit on one page or on separate pages. On one page, each variant must be selectable with its own address, such as a parameter, and there must be one canonical for the whole product. Product variant structured data tells Google how the variants belong together.

Every address should answer with the right code: 200 for pages that exist, 301 for pages that have moved for good, and 404 or 410 for pages that are gone. A page that says “not found” but answers 200 is what Google calls a soft 404.

Avoid chains of redirects. Google says long chains hurt crawling. When you move a page again, update the old redirect so it points straight to the new address.

What to do with sold-out and discontinued products is covered in our e-commerce SEO guide.

Google renders pages with Chromium, but it can only see what is in the rendered HTML. Prices, stock, descriptions and reviews that only appear after a click or a scroll may not be seen.

Links must be ordinary <a href> links. Google cannot follow buttons that only work with JavaScript. Server-side rendering or pre-rendering is still a good idea, Google says, because pages get faster and not all bots can run JavaScript.

Use the URL Inspection tool in Search Console to see the page Google actually received.

Product data with price, currency, availability and reviews tells Google what the page sells. It can make the page eligible for richer results in search, but Google does not promise to show them.

The data must match what the shopper sees. A price changed on the page but not in the data is an error. Check with the Rich Results Test and the rich result reports in Search Console.

Many themes and apps add product data. Check that each product has only one set.

Google measures the experience with three Core Web Vitals. The page's main content should load within 2.5 seconds (LCP), it should respond to clicks within 200 milliseconds (INP), and the layout should not shift (CLS under 0.1). You find the figures in the Core Web Vitals report in Search Console.

Google says good values match what its ranking systems reward, but they guarantee no position. In a store, look especially at large product images, scripts from apps, and banners that push content down as they load.

If you also sell in Sweden, Norway or Germany, use hreflang to tell Google which pages are versions of each other. Each version should point to itself and to all the others.

Do not redirect visitors automatically based on where they are. Google's crawler usually comes from US addresses and could then miss your other versions. Offer a language or country switcher instead.