Should I Block Head Requests to My Website?

Understanding the implications of blocking HEAD requests on your website is crucial. It's generally only recommended if you have a specific reason related to your website's security or functionality. Here's why:

What is a HEAD Request?

A HEAD request is an HTTP method, just like GET or POST. When a client sends a HEAD request to a server, it asks for the headers that a GET request would return. However, it does not return the body of the response. This can be useful for checking what a GET request would return without downloading the entire content. This is particularly useful for:

  1. Checking if a resource exists before trying to download it.
  2. Checking for changes in a resource (through headers like Last-Modified or ETag) to manage caching.
  3. Pre-fetching information about a resource, such as its size or type, without downloading it.

Reasons Not to Block HEAD Requests

  • Caching and Proxy Efficiency: Various web services, including proxies and CDNs (Content Delivery Networks), use HEAD requests to cache content and reduce bandwidth usage efficiently. Blocking these can impact end-users' performance and increase the server load due to unnecessary data transfers.
  • SEO Impact: Some web crawlers use HEAD requests as part of their crawling process to check the validity of links or update their caches. Blocking HEAD requests could impact how your website is indexed.
  • Web Standards Compliance: The HEAD method is a fundamental part of the HTTP/1.1 protocol and is expected to be supported by all web servers as per the standard defined by the IETF (Internet Engineering Task Force). Not supporting HEAD requests can be seen as not adhering to web standards.

Legitimate Reasons to Block HEAD Requests

  • Security Concerns: If you have specific security concerns or have observed malicious actors abusing HEAD requests against your site, you might consider blocking them. However, this should be a measured and monitored approach, as it deviates from standard web practices.
  • Performance Issues: If your server is underperforming and you've identified HEAD requests as a contributing factor, you might temporarily restrict them. However, this is usually a sign of underlying issues that should be addressed directly.

Conclusion

For most websites, blocking HEAD requests is unnecessary and can potentially harm your website's performance and usability. It can also impact how search engines index it. If you're considering blocking HEAD requests for security reasons, exploring other security measures may be a better option to mitigate any risks without entirely turning off a standard and valuable HTTP method.