Spark plugs can be purchased online from specialty parts sites such as Sparkplugs.com, as well as through general automotive supply stores such as Advance Auto Parts. Big box stores like Walmart also sell spark plugs through their websites.
The Sparkplugs.com website offers a wide selection of auto parts in addition to spark plugs, including ignition components, air conditioning and heating components and windshield wiper blades. The site allows users to search by specific part as well as by brand. The site's main search tool prompts users to narrow down potential parts through an interactive list that begins with the vehicle type, such as motorcycle, recreation vehicle or lawn and garden, and moves on to specifics of make and model. As of February 2015, the site also offers a customer satisfaction guarantee that includes full support for processing returns.
When purchasing spark plugs through the Advance Auto Parts website, users have the option to filter results by brand as well as by vehicle. One of the main features of the site is the ability to enter a car's make and model and view all available parts compatible with that vehicle. Users who create an account on the site can store car preferences for further visits.