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Letta (MemGPT) vs LangChain

An open-source framework for building stateful AI agents with long-term memory (formerly MemGPT). Letta lets agents remember, learn and manage their own memory over time, so they improve across conversations instead of forgetting.

Winner: LangChain(⭐ 4.6)

🧠 Expert verdict

Our expert verdict: LangChain is the stronger all-round choice, scoring 4.6/5 versus 4.5/5 for Letta (MemGPT). Choose LangChain if you want the best agents tool overall; pick Letta (MemGPT) if "Stateful agents with long-term memory" matters more for your workflow.

Letta (MemGPT)

An open-source framework for building stateful AI agents with long-term memory (formerly MemGPT). Letta lets agents remember, learn and manage their own memory over time, so they improve across conversations instead of forgetting.

Visit Letta (MemGPT)

LangChain

Open-source framework for building LLM-powered applications and autonomous AI agents with memory and tools.

Visit LangChain
CriteriaLetta (MemGPT)LangChain
Rating
4.5/5
4.6/5
Pricing
Free / Open Source
Free / Open Source
Category
agents
agents
Popularity
👍 Medium
🔥 Very High
Value for Money
⭐⭐⭐ Excellent
⭐⭐⭐ Excellent
📅 Release Date
2023
🔄 Last Update
Aug 2026
Company
Letta
Founded
2023
API Access
Yes
No
Mobile App
No
No

Letta (MemGPT)

Pros

  • +Stateful agents with long-term memory
  • +Agents manage their own memory
  • +Improves over time
  • +Open source and free
  • +Pioneered by the MemGPT research

Cons

  • For developers
  • More complex than stateless bots
  • Setup and tuning
  • Newer ecosystem

🎯 Best forLetta (MemGPT)

Long-lived AI assistantsAgents that learn over timePersonalized companionsMemory-heavy applications

🏷️ TagsLetta (MemGPT)

Open SourceMemoryStateful AgentsFramework

Our Verdict

After comparing ratings, pricing and features, LangChain comes out ahead with a 4.6/5 rating. It is the better choice for most users.

Expert take on each tool

📌 Letta (MemGPT)

Letta (formerly MemGPT) is the go-to open-source framework for stateful agents with real long-term memory: agents that remember and improve instead of resetting each chat. Ideal for developers building assistants meant to last and personalize.

Frequently Asked Questions

Which is better: Letta (MemGPT) or LangChain?

LangChain has the higher user rating (4.6/5 vs 4.5/5), making it the stronger overall pick. That said, Letta (MemGPT) can still be the better fit depending on your budget and specific needs — see the full comparison above.

Is Letta (MemGPT) or LangChain cheaper?

Letta (MemGPT) (Free / Open Source) and LangChain (Free / Open Source) sit at a similar price point. The best way to compare actual cost is to check each tool's plans for the specific features and usage limits you need.

Can I switch from Letta (MemGPT) to LangChain?

Yes — switching between Letta (MemGPT) and LangChain is usually straightforward since both are agents tools with similar core workflows. Most users can export their data and get started with LangChain within a day; just check LangChain's free plan before committing to a paid tier.