Cognition vs Letta
Which Agents AI tool is better in 2026?
Cognition
Applied AI lab building Devin, the AI software engineer.
Letta
Memory-first agents that learn and improve from experience with natural language.
Side-by-side
Cognition leads on both fronts — more capital raised ($2.5B) and a lower entry price than Letta.
| Metric | Cognition | Letta |
|---|---|---|
| Taglinei | Applied AI lab building Devin, the AI software engineer. | Memory-first agents that learn and improve from experience with natural language. |
| Foundedi | 2023🏆 | — |
| HQi | San Francisco, US | US |
| Employeesi | 11-50🏆 | 1-10 |
| Neuron scorei | 84🏆 | 60 |
| Total fundingi | $2.5B🏆 | Undisclosed |
| Latest roundi | Series D · May 2026 | — |
| Valuationi | $26B🏆 | — |
| Cheapest paid plani | Pro · $20/mo🏆 | — |
| Free plani | ✓ Free | ✓ Free |
| Free triali | ✗ | ✓ |
| Top tier pricei | Max · $200/mo | — |
| Pricing summaryi | 5 published plans | 1 published plans |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Cognition and Letta.
| Capability | Cognition | Letta |
|---|---|---|
| MCP support | ✓ | ✗ |
| Public API | ✓ | ✗ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✓ | ✗ |
| SDK languages | — | 1 (Node.js) |
| Free plan | ✓ | ✓ |
| Free trial | ✗ | ✓ |
| Verified | ✗ | ✗ |
| Active deal | ✓ | ✗ |
🟢 Strengths of Cognition
- Has raised more capital ($2.5B vs Undisclosed)
- Higher Neuron score (84 vs 60)
- Lower starting price ($500/mo)
- Newer company (2023)
🔵 Strengths of Letta
- Offers a free trial
Which should you choose?
Choose Cognition if price matters most — it starts at Free · From $500/mo, which is friendlier for teams watching burn. Both AI Agents tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Cognition if you want the most established option — it has raised $2.5B, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
💸 Deals
Try Devin with starter credits
Cognition's Devin offers a starter pack of ACU credits on signup so you can test the autonomous engineer on real tasks.
Terms: Credit amount varies by program.
Frequently asked questions
Cognition vs Letta — which is better?
It depends on your priority. Cognition has raised more capital and is the more established option; Letta has broader feature depth. See the side-by-side table above.
Is Cognition cheaper than Letta?
Yes — Cognition's cheapest paid plan is Pro · $20/mo, while Letta's is Free.
Do Cognition and Letta offer free plans?
Cognition: Yes, has a free plan. Letta: Yes, has a free plan.
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