Technical SEO for web developers: Crawlability and Indexation
Search engines need to reach and understand your pages. If they can’t, your content won’t appear in search results—no matter how good it is.
Crawlability means a search engine can load your pages and follow your links. Indexation means the engine decides to include those pages in its search database. If either part fails, you lose visibility.
What Can Stop a Page From Appearing in Search
You can accidentally block search engines from important content. For example, many sites use a robots.txt file to keep crawlers out of admin pages or login areas. But if you set up this file incorrectly, you might block your blog, products, or entire content folders.
Sitemaps often cause problems too. You should only include pages in your sitemap if they work, matter, and belong in search. If your sitemap lists broken URLs or redirects, search engines may ignore it. They may also trust your signals less in the future.
Sometimes, a page gets left out because you don’t link to it anywhere. These orphaned pages sit in isolation. If you don’t include them in your sitemap either, most search engines will never find them.
To get your pages into the index, you must link to them clearly and list them in an accurate sitemap.
Why a Search Engine Might Skip a Page
Search engines won’t index a page if they receive confusing instructions.
For example, imagine you include a page in your sitemap but also mark it with a noindex tag. Or you set a canonical tag that points to another version—then add noindex to that other version. In both cases, the search engine won’t index either page.
Redirect chains also create problems. If you link to a URL that redirects through two or three steps, the search engine must follow each one. That wastes crawl time and weakens your site structure. Link directly to the final version instead.
Duplicate content can block indexing too. If you publish the same content across many pages and don’t set a preferred (canonical) version, the search engine may decide to skip all of them.
You can prevent this by keeping your signals clean:
Link directly to each important page, use canonical tags correctly, avoid redirect chains, and remove noindex from content you want to rank.
What Google and Bing Will Show You
Google Search Console and Bing Webmaster Tools help you understand how search engines view your site. These tools show you which pages the engines crawled, which ones they skipped, and why.
You can find issues like:
- Pages blocked by
robots.txt - Pages excluded by a
noindextag - Duplicates with no clear canonical
- Pages that were crawled but not indexed
- Pages discovered but not crawled
These tools help you respond to problems. But they only show what happened after the crawl. You can’t use them to prevent issues—you can only react to them.
How to Detect Problems Before Search Engines Do
To stay ahead, run your own site audits using crawl tools that act like search engines. These tools load your site, follow links, and look for broken signals.
Tools like Ahrefs, SEMrush, and Sitebulb scan your full website. They find missing links, long redirect chains, blocked pages, or confusing canonicals. They also explain how to fix these problems.
If you manage a smaller site or just want quick feedback, you can use lighter tools. The Merkle Indexability Checker lets you test one URL at a time. Ubersuggest scans your whole site and points out crawl errors and basic indexation issues.
These tools help you take control. You can fix issues before they reach a search engine’s report.
How to Make Your Pages Easy to Index
To get your content into search, you must build a structure that search engines can follow and trust.
Start by checking that every key page:
- Appears in your sitemap
- Has at least one internal link
- Uses a working canonical tag
- Is not blocked by
robots.txt - Does not include a
noindextag - Avoids long redirect paths
Search engines want a clear signal. Don’t confuse them with mixed instructions or low-quality links. If you guide them well, they will crawl and index your content reliably.
Combine live data from Google Search Console and Bing with regular scans from your own tools. This way, you can fix errors before they cost you traffic.