Rails was complaining about mime types already registered, so I wanted to check what MIME types were already registered in my app.

We can do this easily through Rails console.

# List all registered
Mime::EXTENSION_LOOKUP.map{|x| x}

# Or Check for a specific type
Mime::Type.lookup_by_extension(:pdf)

Related External Links:

• Sean Behan - how-to-get-a-list-of-all-registered-mime-types-in-rails