Indexing is the process of adding a website or a newly created page to a search engine’s directory.
Indexing is the process by which a search engine analyzes previously crawled content and decides whether to include it in its directory, the index.
Indexing occurs in two stages:
First, the crawler—an automated program—visits the page and reads its content.
Then, the search engine decides whether and how to include that page in the index.
Only indexed pages can generally appear in the search engine results, but this does not guarantee an actual ranking.
The process emerged in the 1990s alongside the search engines themselves. In essence, it adapts the concept of systematic directories found in libraries and reference works to the digital age.
Over the years, indexing has become increasingly sophisticated, as search engines must select and rank the most relevant websites from among billions.
Without indexing, a website won’t appear in search results. It may have the best content, look great, and feature the most sophisticated functions, but if it isn’t indexed, all of that is for nothing and the site won’t be found.
It’s important to keep an eye on indexing to ensure that important pages are actually included and that duplicate or unimportant pages are left out.
Not every page is automatically indexed. Duplicate, low-quality, or hard-to-reach pages are sometimes not crawled at all or only rarely, or they may not be indexed after crawling.
Technical errors, such as accidental blocking, can also exclude pages without anyone noticing. For large websites, it’s also important to prioritize which pages to focus on, since search engines limit the resources they allocate to each website.
A company launches a website relaunch. Traffic plummets. An indexing block accidentally activated during the redesign remained in place.
As a result, the new site was practically invisible to Google. Only after the block was removed were the pages gradually indexed. This also restored the site’s visibility.