Second brain apps promise compounding returns on what you read and think. The leaders differ on whether your atoms are markdown files, database rows, or outline blocks.
Obsidian remains the default serious answer for many people. Notion fits when projects and notes share one home. Capacities targets object-based thinkers. Logseq suits journal-first linkers.
The short answer
Start with Obsidian for file-based PKM, Notion for workspace PKM, Capacities for object networks, Logseq for outline-heavy daily notes.
Top picks
Best best second brain apps
Balances power with files you can inspect outside the app.
Useful when your thinking feeds operational work weekly.
Appeals when you want networks beyond classic pages and folders.
Second brain is a behavior, not a template pack
Apps help, but retrieval habits matter more than dashboards.
Pick one inbox pattern, one weekly review, and stop adding novelty folders.
Linking vs categorizing
Obsidian and Logseq push links and mentions. Notion can mimic graphs with relations.
If you hate links, forcing a graph tool will fail.
Objects when tables beat paragraphs
Capacities shines when entities repeat: people, papers, concepts with properties.
If everything is a one-off essay, markdown pages may stay simpler.