This guide explains how to obtain information about the presence of a caching system on a website using the curl command.

Preamble

• In the world of programming and system administration, it is often necessary to determine if a website uses a caching system to improve its performance.
• Caching systems like Fastly are commonly used to temporarily store data to serve it faster to users.
• By following these steps, you will be able to determine if a website uses a caching system to improve its performance and understand the operation and optimization of websites.

Using the curl command

curl is a command-line tool for transferring data using URLs.

The -svo /dev/null option is used to perform a silent request (-s), display detailed information about the request (-v) and redirect the output data to /dev/null to ignore it (/dev/null is a special device on Unix/Linux systems that acts as a trash can). -H "Fastly-Debug: true" is an HTTP header added to the request to request specific Fastly debugging information.

Execute the command

Run the following command from a Terminal type application (command-line interface, CLI / Command Line Interface) on your device:

curl -svo /dev/null [url] -H “Fastly-Debug: true”

and replace [url] with the address of the website you want to check.

If the site uses Fastly or another similar caching system, you will see specific debugging information in the command output. The details provided may include information about HTTP requests and responses, as well as information about the cache and performance.