Google Updates Robots.txt Policy: Unsupported Fields Now Clearly Ignored
Google has updated its robots.txt policy, clarifying that unsupported fields will be ignored by its crawlers. Website owners should use only documented fields like user-agent, allow, disallow, and sitemap, while reviewing their existing files to ensure compliance with Google’s official guidelines.
Google has updated its Search Central documentation, clarifying its stance on unsupported fields in robots.txt files, a move aimed at minimizing confusion for webmasters and developers.
The Key Update
In this recent clarification, Google emphasizes that its crawlers only recognize fields explicitly listed in its robots.txt documentation. This means that any fields not officially supported will be ignored by Google’s crawlers, even if other search engines might use them.
According to Google:
“We sometimes get questions about fields that aren’t explicitly listed as supported, and we want to make it clear that they aren’t.”
This update reinforces the importance of adhering strictly to Google’s documented guidelines when configuring robots.txt files, as relying on unsupported fields could lead to unintended crawling behavior.
What This Means for Website Owners and Developers
- Use Only Supported Fields: To ensure proper functionality, website owners should stick to the fields explicitly mentioned in Google’s official documentation.
- Review Your Robots.txt File: It’s crucial to audit your existing robots.txt file to ensure it doesn’t contain unsupported or non-standard directives that Google will ignore. Failing to do so may result in pages being crawled in unintended ways.
- Know the Limits: Google’s crawlers will not process third-party or custom directives. For instance, while some search engines might recognize fields like “crawl-delay,” Google does not support them.
Supported Fields
As of the latest update, the fields officially supported by Google include:
- user-agent
- allow
- disallow
- sitemap
These fields should be used carefully to control how Google crawls your website. For instance:
- user-agent specifies which search engines the directives apply to.
- allow and disallow control which pages Google can or cannot access.
- sitemap informs Google about the location of your sitemap to improve crawling efficiency.
Commonly Used Directives Google Does Not Support
Although Google hasn’t listed unsupported fields explicitly, this update suggests that Google doesn’t recognize directives like crawl-delay—a field some website owners use to slow down crawler requests to reduce server load. However, Bing and other search engines may still honor such directives. Additionally, Google is phasing out support for the ‘noarchive‘ directive, signaling further changes in how they manage certain content in search results.
Why This Matters
Google’s robots.txt update serves as a reminder for webmasters to remain vigilant about staying compliant with official guidelines. Unsupported fields could cause unnecessary confusion and lead to poor SEO outcomes if misused. Website owners should rely on the documented features and avoid assuming that non-standard directives will be effective.
Looking Ahead
To optimize website performance in search, staying up-to-date with Google’s Search Central is vital. Regularly reviewing their guidelines and understanding best practices for robots.txt files ensures that Google crawlers index your site as intended, boosting SEO and avoiding any crawling issues.
