--- title: "LangGraph vs Letta: Which is Better in 2026? | App Stack Builder" description: "LangGraph vs Letta compared for 2026 — pricing, free tiers, features, pros & cons. See which agent framework tool is the better fit for your startup." source: https://appstackbuilder.com/compare/langgraph-vs-letta retrieved: 2026-10-29 --- ![](https://www.google.com/s2/favicons?domain=langchain.com&sz=128) vs ![](https://appstackbuilder.com/logos/letta.png) # LangGraph vs Letta: Which is Better in 2026? Agent Framework Choosing between [LangGraph](https://appstackbuilder.com/tools/langgraph) and [Letta](https://appstackbuilder.com/tools/letta)? Both are popular agent framework tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack. LangGraph is for: Teams building long-running, multi-step agents that need explicit state, loops, human approval steps and checkpoints they can audit. Letta is for: Teams building agents that must remember users and context across sessions and restarts, with memory as the core design. Quick verdict There’s no single winner; pick on your constraint. Choose LangGraph if your agent runs many steps and you need explicit control over state and transitions. Choose Letta if your agent must remember users and past sessions over weeks or months. ## LangGraph vs Letta — Side by Side | | LangGraph | Letta | | --------------------- | ------------------------------------------------------------------ | ------------------------------------------------------------------------ | | Category | Agent Framework | Agent Framework | | What it is | Code library: graph-based agent orchestration | Agent server and SDKs: agents with persistent memory | | Languages | Python, JavaScript/TypeScript | Python and TypeScript SDKs | | Licence | MIT | Apache 2.0 | | Managed / paid option | LangSmith Deployment (usage-based, from LangSmith Plus) | Letta API: free tier, Pro $20/month plus usage | | Project status | Active; 1.x | Active | | Pricing | Free · then usage-based | Free · paid from $20/mo | | Starting price | Free tier available | Free tier available | | Free tier | ✓ | ✓ | | Rating | 4.5 | 4.0 | | Best for | Agent Framework — stateful agents, human-in-the-loop, durable runs | Agent Framework — long-term memory, stateful agents, self-host or hosted | ## Pros & Cons ![](https://www.google.com/s2/favicons?domain=langchain.com&sz=128) [LangGraph](https://appstackbuilder.com/tools/langgraph) * ✓Fine-grained agent control * ✓Great for complex multi-step flows * ✓Open-source * ✓Integrates with LangChain & LangSmith * ✗Steeper learning curve * ✗Newer than core LangChain ![](https://appstackbuilder.com/logos/letta.png) [Letta](https://appstackbuilder.com/tools/letta) * ✓Memory is the design centre, not an add-on * ✓Agents survive restarts with state intact * ✓Comes from the MemGPT paper * ✗Younger project with a moving API * ✗Memory model is opinionated ## Key Features Compared ### LangGraph * ✓Agents modelled as state graphs with loops and parallel branches * ✓Checkpoints that persist state and let a run resume * ✓Human-in-the-loop interrupts and approval gates * ✓Python and JavaScript/TypeScript libraries * ✓Managed hosting through LangSmith Deployment (formerly LangGraph Platform) * ✓MIT licence ### Letta * ✓Persistent, self-editing agent memory (from the MemGPT research) * ✓Agents keep their state across restarts * ✓Self-hosted server, or the hosted Letta API * ✓Hosted plans: free tier and Pro at $20 a month with pay-as-you-go usage * ✓Letta Code, an open-source coding agent with memory across sessions * ✓Apache 2.0 licence ### Choose LangGraph if… * ✓Your agent runs many steps and you need explicit control over state and transitions. * ✓You need human approval steps or the ability to pause and resume runs. * ✓You want a managed deployment option from the same vendor. [LangGraph review & pricing ](https://appstackbuilder.com/tools/langgraph) ### Choose Letta if… * ✓Your agent must remember users and past sessions over weeks or months. * ✓You want agents that keep state when the process restarts. * ✓You want the choice of self-hosting or a hosted API. [Letta review & pricing ](https://appstackbuilder.com/tools/letta) ## Frequently Asked Questions Is LangGraph better than Letta?⌄ There’s no single winner; pick on your constraint. Choose LangGraph if your agent runs many steps and you need explicit control over state and transitions. Choose Letta if your agent must remember users and past sessions over weeks or months. What is the difference between LangGraph and Letta?⌄ What it is — LangGraph: Code library: graph-based agent orchestration. Letta: Agent server and SDKs: agents with persistent memory. Languages — LangGraph: Python, JavaScript/TypeScript. Letta: Python and TypeScript SDKs. Licence — LangGraph: MIT. Letta: Apache 2.0\. Managed / paid option — LangGraph: LangSmith Deployment (usage-based, from LangSmith Plus). Letta: Letta API: free tier, Pro $20/month plus usage. Project status — LangGraph: Active; 1.x. Letta: Active. LangGraph vs Letta: which is cheaper?⌄ LangGraph pricing: Free · then usage-based. Letta pricing: Free · paid from $20/mo. Confirm current pricing on each tool's official site, as plans change. Which is rated higher, LangGraph or Letta?⌄ In our catalog, LangGraph rates 4.5 out of 5 and Letta rates 4.0 out of 5, so LangGraph has a slight edge on reviews. When should I skip both LangGraph and Letta?⌄ Skip LangGraph if you want to prototype a multi-agent workflow in a few lines. CrewAI’s role-based crews are quicker to start. Skip Letta if you only need short-lived task agents. A lighter SDK is simpler. Sources · tool facts checked October 2026 1. 1.[LangSmith pricing (LangChain)langchain.com ](https://www.langchain.com/pricing) 2. 2.[Letta Code (Letta docs)docs.letta.com ](https://docs.letta.com/letta-code) See more options in our guide to the [best agent framework tools for startups](https://appstackbuilder.com/categories/agent-framework). ## Still not sure which to pick? Get a free, AI-powered tech stack — including the best agent framework pick for your budget and team — in 60 seconds. [Build my stack free ](https://appstackbuilder.com/build-stack)