According to Google’s December crawling article, sites should host resources like JavaScript and CSS on third-party domains or CDNs to improve crawl efficiency. This affects how Google allocates its crawl budget.

You can find the full resource here: Crawling December: The how and why of Googlebot crawling

Impact on Crawl Allocation

When resources are hosted on your main domain:

• Counts against your site’s crawl budget
• Reduces time for HTML page crawling
• Affects overall crawl efficiency

Google’s Recommendations

Google suggests:

• Using CDNs for resource hosting
• Implementing separate subdomains
• Moving JavaScript and CSS off main domain

Implementation Strategy

For larger websites:

• Migrate heavy resources to CDNs
• Use separate subdomains for asset hosting
• Prioritize HTML content for main domain crawling

Conclusion

While smaller sites may not need to worry, large-scale websites should consider moving resources to third-party domains or CDNs to optimize their crawl budget allocation and improve overall search engine performance.