Example: "I found the information on website."
: Use "a" or "an" only if you are describing it as one of many similar things (rare for a specific domain). Example: "Is fittrack.com a health tracking site?" fittrack.com
: Use "the" when you are referring to the website as a specific entity or object. Example: "I found the information on website
When referring to the website , the proper article to use depends on how you are using the name in a sentence: "Log in to fittrack.com").
In most casual and professional writing, you treat the URL like a name and do not use an article (e.g., "Log in to fittrack.com").