# Letta vs Mem0: license, pricing and features compared (October 2026)

Canonical: https://theagenticweekly.com/compare/letta-vs-mem0 · Last verified: 2026-10-26 · Published: 2026-10-25 · Author: Agentic Weekly (operated independently from Texas, US) · Evidence: Evidence: Mem0 has a Tested entry; Letta is Reported (scope on each tool page). The facts in the tables were read from each vendor's own pages and the public GitHub API on 2026-10-25 (America/Chicago) and are Reported. The What we measured section lists what we have actually run, with links to the test logs, and what we have not run yet; anything we could not confirm is marked as not captured.

**Our pick:** Pick Letta for agents that must remember across sessions; pick Mem0 for apps that need long-term per-user memory. No overall winner: we have not benchmarked them against each other. **Updated:** 2026-10-26 (America/Chicago).

> Letta and Mem0 are both listed under Agent building. GitHub stars on Oct 25, 2026: Mem0 67,804 (mem0ai/mem0) vs Letta 25,254 (letta-ai/letta). Stars measure attention, not quality. Latest release we saw: Mem0 Python SDK v2.2.1 on Sep 25, 2026; Letta v0.16.8 on May 14, 2026 (134 days earlier). Letta is the better fit for: agents that must remember across sessions. Mem0 is the better fit for: apps that need long-term per-user memory. Facts were read from vendor and GitHub pages on Oct 25, 2026 and are Reported; what we ran ourselves is under What we measured.

## What we measured

We have run Mem0 ourselves but not the other tool, so no head-to-head result exists yet. Everything else on this page is Reported from vendor and GitHub pages.

Table: Our own tests for Letta and Mem0

| Test | Letta | Mem0 |
|---|---|---|
| Hands-on test log (install and a real task) | Not tested yet. What we will run: install, then the same one-tool agent task five times, with install time and pass rate. | Tested: Mem0 mem0ai 2.2.1 (open-source Python SDK), Oct 26, 2026: passed. Mem0's open-source SDK 2.2.1 stored a fact from one chat message with a local 3B model and retrieved it with a semantic search (2.04 s) on the second attempt; the first… [Full test log](https://theagenticweekly.com/tests/mem0) |

How we test and label results: [methodology](https://theagenticweekly.com/methodology#testing-rig). All test logs: [test hub](https://theagenticweekly.com/tests).

## Letta vs Mem0 at a glance

Letta and Mem0 are both listed under Agent building. Agentic Weekly's Letta page names Mem0 as an alternative. Letta: Platform and open-source framework for stateful agents that keep and improve memory across sessions. Mem0: Open-source and hosted memory layer that lets agents remember users across sessions, with a free tier and published request quotas.

Table: Letta and Mem0 side by side (vendor pages and GitHub, 2026-10-25)

|  | Letta | Mem0 |
|---|---|---|
| Vendor | Letta | Mem0 |
| Listed under | Agent building | Agent building |
| License | Apache-2.0 | Apache-2.0 |
| Pricing model | Freemium | Freemium |
| Free tier | Free: $0; includes limited agents and LLM requests with rotating free models | Free: 10,000 add requests and 1,000 retrieval requests per month |
| Paid plans | $20 per month plan; Teams $20 per seat per month; usage items such as $0.10 per active agent per month; Enterprise custom | $19 per month (50,000 add / 5,000 retrieval); $249 per month (500,000 add / 50,000 retrieval); Enterprise custom |
| Platforms | Cloud platform, CLI and open-source server | API, Python and JS SDKs, open-source self-host |
| Public repository | letta-ai/letta: 25,254 stars, last push Oct 18, 2026 UTC (GitHub API, Oct 25, 2026) | mem0ai/mem0: 67,804 stars, last push Oct 23, 2026 UTC (GitHub API, Oct 25, 2026) |
| Latest release we saw | v0.16.8, May 14, 2026 | Python SDK v2.2.1, Sep 25, 2026 |
| Evidence | Reported from vendor pages | Tested (scope on its tool page) |

## How Letta and Mem0 differ

- GitHub stars on Oct 25, 2026: Mem0 67,804 (mem0ai/mem0) vs Letta 25,254 (letta-ai/letta). Stars measure attention, not quality.
- Latest release we saw: Mem0 Python SDK v2.2.1 on Sep 25, 2026; Letta v0.16.8 on May 14, 2026 (134 days earlier).
- Free tier: Letta: $0; includes limited agents and LLM requests with rotating free models. Mem0: 10,000 add requests and 1,000 retrieval requests per month.
- Plans and prices differ and are not like-for-like (credits, seats and usage limits vary), so we do not name a cheaper tool. The Paid plans row above quotes each vendor's plan list as read on Oct 25, 2026.
- Platforms as the vendors list them: Letta: Cloud platform, CLI and open-source server. Mem0: API, Python and JS SDKs, open-source self-host.

Both carry the same license: Apache-2.0. Both are listed as "Freemium", so compare the plan tables rather than the model.

## Which should you pick?

- Pick Letta if: agents that must remember across sessions. Skip it if: you want a stateless simple chatbot.
- Pick Mem0 if: apps that need long-term per-user memory. Skip it if: you only need a vector database.

## Strengths and limits

Table: Strengths and limits as listed on each tool page

|  | Letta | Mem0 |
|---|---|---|
| Strengths | Apache-2.0; Memory-first design | Published quotas; Open-source option |
| Limits | Credit-based usage can add up for long sessions | Add and retrieval quotas are separate |

## What we did not verify

- Letta: Behavior in practice (we have not run this tool).
- Mem0: Benchmark claims (vendor).
- Output quality, speed and reliability beyond the smoke tests listed under What we measured: not compared.

## FAQ

### Is Letta or Mem0 open source?

Letta: Apache-2.0. Mem0: Apache-2.0. Licenses come from each project's GitHub repository or the vendor's own pages, read Oct 25, 2026; read the license text itself before redistributing or building a competing service.

### Does Letta or Mem0 have a free plan?

Letta: Free: $0; includes limited agents and LLM requests with rotating free models. Mem0: Free: 10,000 add requests and 1,000 retrieval requests per month. Checked Oct 25, 2026; prices and limits change, so confirm on each vendor's page.

### Which was updated more recently, Letta or Mem0?

Letta's newest release we saw is v0.16.8 (May 14, 2026); Mem0's is Python SDK v2.2.1 (Sep 25, 2026). Read Oct 25, 2026 from the official release page or repository; a newer date is not a quality ranking.

### What is the main difference between Letta and Mem0?

GitHub stars on Oct 25, 2026: Mem0 67,804 (mem0ai/mem0) vs Letta 25,254 (letta-ai/letta). Stars measure attention, not quality. Latest release we saw: Mem0 Python SDK v2.2.1 on Sep 25, 2026; Letta v0.16.8 on May 14, 2026 (134 days earlier).

## Sources

- [Letta](https://www.letta.com/) (fetched 2026-10-25)
- [Letta pricing](https://www.letta.com/pricing) (fetched 2026-10-25)
- [Letta repository (GitHub)](https://github.com/letta-ai/letta) (fetched 2026-10-25)
- [Mem0](https://mem0.ai/) (fetched 2026-10-25)
- [Mem0 pricing](https://mem0.ai/pricing) (fetched 2026-10-25)
- [Mem0 repository (GitHub)](https://github.com/mem0ai/mem0) (fetched 2026-10-25)

## Related

- [Letta facts and sources](https://theagenticweekly.com/tools/letta)
- [Mem0 facts and sources](https://theagenticweekly.com/tools/mem0)
- [Agent building: all tools we track](https://theagenticweekly.com/best/agent-building)
- [Mem0 vs LangChain](https://theagenticweekly.com/compare/mem0-vs-langchain)

## Changelog

- 2026-10-25: First published. Facts read from vendor pages and the GitHub API on 2026-10-25.

## How to cite

Agentic Weekly, "Letta vs Mem0: license, pricing and features compared (October 2026)", last updated 2026-10-26, https://theagenticweekly.com/compare/letta-vs-mem0