If a crawler cannot access content behind a login page, why that content still appears in search engine results
- Steven Willers
- Aug 10, 2024
- 3 min read
In the most technical part the crawler of the search engine can’t index and view the website that are covered by the blanket of a login page . But of you still search a query for request of a data on that magnifying glass it will appear , with the same login page. Now if the search engine can’t access it how it indexed it during serving.
If you still don’t believe confirm it by searching on web (and sticking on the login page once) .
Got exhausted, look , Google confirms that their crawler(more precisely Googlebot) can’t access the data located behind a login wall(login page).
Metadata
Maybe Google statement is wrong, but as a programmer what I know can think of it as in the step of metadata of the page; even if the full content is behind a login, parts of the content, like titles, descriptions, or metadata, may be exposed to crawlers. This metadata can be indexed and appear in search engine results.Some websites provide a snippet or preview of the content (like the first few lines of an article) to search engines, allowing them to index and show it in search results while the full content remains behind a login.
User – Submitted content
Assume , you submit content from behind a login page in the form to documents , text ,et cestra to public forums on other platforms with a key or query . These publicly accessible platforms then get crawled by search engines, indirectly exposing the content and indexed in your feed.
Even if the original content was behind a login page, it’s now accessible through the public platforms.
Cached Version of Content
The content might exist in a publicly accessible form elsewhere on the website that doesn’t require login. Like you took , the text from a that proxy held webpage copied it and push it in your own web page with a direct link.The crawler accidentally crawls your website calculates wheter the given link must be indexed or not and send it for serving .
This version of the content could have been indexed by the crawler before it was placed behind the login page. Search engines might show this cached or publicly indexed version even if the current version requires a login.
In this case , the more text resource and urls the crawler found over the crawled-internet about the login covered page and the key with query the more confirmed it is to push it in on the internet. This is also the reason why storing a word in a tree data structure, like a trie or suffix tree, may require additional space beyond the length of the word itself as the crawler itself stores such data.
Search Engine Partnerships
Some websites have agreements with search engines, providing them with special access to content behind a login. The search engine can crawl and index this content but only show it to users in specific formats (this doesn’t mean the search engine takes fund to serve you page at the head) e.g. the news websites (e.g., The New York Times, Wall Street Journal) partnering with Google to provide limited access to articles.
Search Engines Mimicking Logged-In SessionsAuthenticated
Some search engines have advanced capabilities where they can mimic logged-in sessions, especially if granted permission or access by the site, allowing them to index content behind login walls. However, there are cases too I find refering to it .
Content Leaks
There might be a security flaw or misconfiguration where content intended to be behind a login is mistakenly exposed to crawlers. In such cases, the crawler can index this content before the issue is fixed.The most surprising example I found was the facebook’s photo exposure (2019): A bug in Facebook’s photo feature allowed users to access photos that were not meant to be public, including photos that were uploaded but not yet posted.
Browser Caching
Browser caching is a feature that stores frequently-used resources locally on a user’s device to speed up browsing. Sometimes, a user’s browser cache might store content from behind a login, and if the crawler has access to this data (through proxy or other means), it could potentially be indexed.
References:
-Steven Willers
Ps : If you are still here: https://www.google.com/search?q=what+is+the+airspeed+velocity+of+an+unladen+swallow
