Which website is commonly used for event registration in many races?

Active.com is widely recognized as a go-to platform for event registration, particularly in the context of races and sporting events. This website specializes in helping users find and register for various sporting activities, including running races, triathlons, and other fitness-related events. It provides comprehensive features that allow race organizers to set up events and manage registrations efficiently, building a strong community around athletic participation.

The other options offer different services. Runnersworld.com focuses primarily on running news, training tips, and gear reviews, serving as a resource for enthusiasts rather than a dedicated registration platform. RaceEntry.com also facilitates race registrations but may not have the same level of recognition or user base as Active.com. Eventbrite.com is primarily known for a wide range of event management and ticketing solutions, spanning different types of events, but it does not cater specifically to the niche of sporting events in the same way that Active.com does.