Which one should you pick?
Mem0
Build with Mem0 if memory is a feature of something you are shipping. Its platform handles operations for you, its open-source edition is pluggable, and its graph memory does entity linking properly.
Second Brain
Take Second Brain if the memory is yours. You are a consultant or a developer whose thinking is scattered across ChatGPT, Claude and Cursor, and you want a year of it to pile up in one place you own, with no meter and no plan to outgrow.
If you want both, they coexist: Second Brain for your own context, Mem0 inside the product.
How they compare
| Criterion | Second Brain | Mem0 |
|---|---|---|
| Where the memory lives | In your Cloudflare account: D1, Vectorize and the Worker all inside it, unreadable to the maintainers. | On the cloud platform, Mem0’s servers in your Mem0 account; with the open-source edition, your own infrastructure. docs.mem0.ai/platform/mem0-mcp, checked 6 Sep 2026. docs.mem0.ai/open-source/quickstart, checked 6 Sep 2026. |
| Who can read it | You, from any MCP client or the dashboard, over OAuth. | Holders of your account’s API keys, or the per-user keys the self-hosted server issues. docs.mem0.ai/platform/mem0-mcp, checked 6 Sep 2026. |
| Tools and sources | Any MCP client (Claude, Claude Code, ChatGPT, Cursor and the rest), plus Obsidian, Notion, read-only calendar and email, iOS Shortcuts, the CLI and a bookmarklet. | A hosted MCP server reaches Claude, Claude Code, Codex, Cursor, Windsurf, VS Code and OpenCode, with OpenMemory as the project-scoped option for coding agents. docs.mem0.ai/platform/mem0-mcp, checked 6 Sep 2026. mem0.ai/openmemory, checked 6 Sep 2026. |
| Coherence over months | Every capture is compared by meaning: contradictions settle on the newer belief with the older kept for audit, near-duplicates merge or replace, and 95 per cent matches are blocked. | The platform does add and update extraction, graph entity linking and Dream consolidation, the last two on Pro and Enterprise; the open-source edition’s coherence mechanics are not documented in Mem0’s public docs. mem0.ai/pricing, checked 6 Sep 2026. |
| Teams | Personal and shared layers on one Worker, private by default, at no extra charge. | Unlimited end users on every tier, organized by user, agent, app and run; no shared-layer equivalent advertised. mem0.ai/pricing, checked 6 Sep 2026. |
| Cost | Free at personal scale inside Cloudflare’s free tier; MIT-licensed forever, no paid tier. | Hobby free (10,000 adds a month, one project), Starter $19 a month, Pro $249, Enterprise custom; the open-source edition is free software plus your infra and model costs. mem0.ai/pricing, checked 6 Sep 2026. |
| Setup | The desktop app provisions the database, index and Worker in about two minutes, no terminal. | Cloud is a sign-up and one npx command; the open-source server is pip or npm plus model and store config, then Docker Compose. docs.mem0.ai/open-source/quickstart, checked 6 Sep 2026. |
| Export | JSON backup and Markdown export from the dashboard, with restore. | A dashboard at app.mem0.ai and documented MCP delete tools; we could not verify a formal export feature. docs.mem0.ai/platform/mem0-mcp, checked 6 Sep 2026. |
| License | MIT. | Apache-2.0. github.com/mem0ai/mem0, checked 6 Sep 2026. |
Where Mem0 wins
Mem0 wins as infrastructure. The open-source edition takes pluggable LLMs, embedders, vector stores and rerankers, so it fits whatever stack you already run. The managed platform brings SLAs, SSO and audit logs, which matter the moment memory sits inside a product with customers. Graph memory with entity linking is a real capability Second Brain does not have; Second Brain has relationship links between memories, not a graph database. And with about 65,000 stars, the ecosystem around it is far larger than Second Brain’s.
Common questions
Can Second Brain replace the Mem0 API in my product?
No. Mem0 builds memory into applications through an API you call; Second Brain is a finished, self-hosted brain you use through AI tools. If your product needs a memory service with SDKs and metered requests, Mem0 is built for that job. Second Brain is built for the person doing the thinking.
Both are open source. What actually differs?
License aside, Apache-2.0 against MIT, the difference is assembly. Mem0’s open-source edition expects you to supply the model, the vector store and the config, then run the server yourself. Second Brain’s desktop app provisions the database, the vector index and the Worker in your Cloudflare account, and wires up Claude Code and Cursor along the way.
Does Second Brain send my data to OpenAI or Anthropic?
No. Embeddings and the language model run on Cloudflare Workers AI inside your own account. Nothing goes to OpenAI or Anthropic, and the maintainers cannot read your memories, because the data was never on their servers.
Does Second Brain do graph memory?
Not as a graph database. Memories carry relationship links you can follow, from a decision to what it caused or relied on, which covers most personal use. If you need entity-relationship graphs at scale, Mem0’s graph memory, on Pro and above, is the better fit.
What does Second Brain cost?
Nothing, and that is a commitment rather than a launch price: free and MIT-licensed forever, self-hosted only. Personal use fits inside Cloudflare’s free tier. There is no paid tier and there will not be one; your Cloudflare account is the only vendor involved.
Sources
- mem0.ai/pricing (checked 6 September 2026)
- docs.mem0.ai/open-source/quickstart (checked 6 September 2026)
- docs.mem0.ai/platform/mem0-mcp (checked 6 September 2026)
- github.com/mem0ai/mem0 (checked 6 September 2026)
- mem0.ai/openmemory (checked 6 September 2026)
- github.com/rahilp/second-brain-cloudflare and its wiki (checked 6 September 2026)