Introduction to technical SEO

Why are broken links bad?

You may think SEO (Search Engine Optimization) is all about making the content on your site relevant with H1, H2 etc; and using the best search words so visitors will find you? That’s good, but if your site has broken links search engines will still give you a bad ranking.

Some day, all of us will have to delete a page or just rename a page. If we don’t take care, visitors will see a 404 Not Found page at the old URL. And even worse, search engines will think your site is not relevant and will give you bad search engine ranking.

How does search engine crawlers work?

Technical SEO is when search engines crawl your website to index it. For example, you might have 1000 pages but only 670 pages are relevant. Then you want to hide the other 330 pages from crawlers. With a well-defined robots.txt you can make search engines avoid indexing non-relevant pages.

It takes a crawler a few seconds to crawl through a website. Crawlers check if your content is relevant. They look if you have a good semantic structure with a single H1, followed by H2s, followed by H3s, and so on. A crawler also checks if a website has duplicate content, TITLE-tags for pages, ALT-text for images, META-tags for page description etc. This is called content SEO.

A crawler has a budget on how many pages it has time to crawl at a website. If a crawler hits a 404 Not Found page it may decide this website is not well maintained, and not worth its crawl time.

What about canonical URLs and duplicate content?

With a canonical URL you suggest to a crawler the most relevant URL of a resource with more than one URL, for example “about-us” and “about-us/”. Without a canonical URL a crawler may decide you have duplicate pages just to get higher ranking, and will penalise you with lower ranking.

Let’s say you have one page in English and one page in Swedish, but you want a film resource to be shown for both languages. You can use a canonical URL to tell a search engine that, even though you have duplicate content (in this case the film), the film is relevant in both pages. Using a canonical URL for the film will not risk lower your search engine ranking.

When using a canonical URL you suggest to a crawler that this is the most relevant URL for a resource. When using a redirect (301) you are directing a visitor to a specific page.

However, a crawler can ignore canonical URLs if they don’t match reality, so they must be correct.

Can I help crawlers?

Yes, add a sitemap. A sitemap is exactly what it sounds like, a map of your site’s resources. When you add a resource to your site an updated sitemap will help a crawler find that your site is relevant for that particular resource.

SEO Toolbox

How can SEO Toolbox help?

Every second site contains at least one broken link so this issue affects both small sites and bigger multilingual sites with thousands of pages. Concepts above might seem confusing. You don’t have to be an expert in technical SEO when using SEO Toolbox as most things works automatically in the background, so you can focus on creating engaging content. For simple use, just install SEO Toolbox and forget about it.

If you’re an Optimizely(Episerver) admin you can create redirects manually. Let’s say a page is not broken but you would like to ”hide” the page temporary. Just add your own redirect (302) in SEO Toolbox. That’s a temporary redirect. You can also redirect a page permanently (301), of course!

Do you have a rebuilt website and need to migrate URLs to not loose search engine ranking? You can easily import and export URLs with SEO Toolbox. For example, you can import URLs to SEO Toolbox from Google Search Console.

David Ärlebrand

David Ärlebrand

Product Manager
+46 734 38 25 16

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