Updated September 2019 after the most recent price increase
Asana's pricing structure has changed several times since it was founded in 2008. They have always offered a very generous free version that many small businesses and nonprofits embraced. Originally, they allowed 20 free users with unlimited projects. Virtually all the features (except for a few privacy settings) were included, and they targeted larger businesses who needed 20+ seats as their first paying customers.
Today, Asana still offers a wonderful free project management solution up to 15 people, but many features (Portfolios, Search Reports, Custom Fields, Dependencies) are reserved for paying customers. Let's discuss which plan is right for your organization.