Tana

Tana is a powerful, AI-enhanced note-taking and knowledge-management tool built around a flexible outliner that turns your notes into structured, connected data. Rather than flat documents, Tana lets you capture thoughts as nodes that can be tagged, given fields and linked together, so your notes become a queryable, structured knowledge base. With supertags, custom fields and AI assistance woven in, it appeals to people who want to organize complex information and build a genuinely powerful "second brain."

Its strengths are structure, flexibility and AI. The outliner-plus-supertags model lets you impose rich structure on your notes without rigid templates, so the same information can be viewed, filtered and connected in many ways — a level of power that resonates with knowledge workers, researchers and serious note-takers. AI features help capture, organize and surface information, reducing the manual work of maintaining a knowledge system. For those who find simple note apps too limiting and want their notes to behave more like a flexible database, Tana offers exactly that depth.

Tana is a great fit for power users, researchers, founders and knowledge workers who want a flexible, structured, AI-assisted tool for managing complex information and building a connected knowledge base. It sits alongside tools like Notion, Obsidian, Capacities and Reflect in the note-taking and "second brain" space, distinguished by its outliner-and-supertags approach and AI. If you think in connections and structure and want a note tool powerful enough to model your knowledge rather than just store it, Tana is a compelling, capable choice worth exploring.