Best AI Memory Frameworks in 2026— Ranked & Compared
We tested eight major AI memory frameworks on the LongMemEval benchmark, compared pricing from free to $1,970/month, and evaluated each on architecture, local-first capability, and developer experience. MemPalace leads the ranking with 96.6% raw accuracy at zero cost. Here is the full breakdown.
How We Ranked These Frameworks
Every framework was evaluated across five dimensions. We weighted benchmark accuracy highest because memory systems exist to recall information correctly — everything else is secondary.
- 1LongMemEval benchmark — the standard multi-session recall test. We used raw accuracy (no LLM post-processing) where available, and noted frameworks that have not published scores.
- 2Pricing— monthly cost for a solo developer and for a 10-person team. Free wins.
- 3Ease of setup — time from zero to working memory in a local dev environment.
- 4Local vs cloud — whether it runs fully offline, requires a cloud account, or both.
- 5Features— MCP tooling, knowledge graphs, embedding options, and ecosystem integrations.
The Rankings
Eight frameworks, ranked from best to worst overall. Each card shows the benchmark score, pricing, and what the framework does best.
MemPalace
Top PickBest for: Developers who want accuracy + privacy.
MemPalace stores every conversation verbatim and uses AAAK compression plus vector search to find relevant memories. It scores 96.6% raw on LongMemEval (100% with optional Haiku reranking), runs entirely locally on SQLite + ChromaDB, and ships with 19 MCP tools for Claude Code integration. No API keys, no cloud accounts, no monthly bills. MIT-licensed and open-source.
Zep / Graphiti
Best for: Apps needing temporal reasoning.
Zep's Graphiti engine builds a temporal knowledge graph that tracks when facts were true — ideal for apps where “when did this change?” matters. Cloud tiers range from free to $475/month. Self-hosting is available but requires more infrastructure than SQLite-based solutions. Strong pick for customer-facing chatbots and support systems.
Full comparisonMem0
Best for: Enterprise teams wanting managed service.
Mem0 uses LLM extraction to decide what to remember, which makes it compact but risks losing context the model deems unimportant. Backed by $24M in YC funding with 48k+ GitHub stars. Cloud pricing runs $19 to $249/month. The open-source version can run locally but lacks some cloud-only features like the managed knowledge graph.
Full comparisonLetta (MemGPT)
Best for: Autonomous agents with self-editing memory.
Letta (formerly MemGPT) introduces self-editing memory where agents autonomously decide what to store, update, and delete. No published LongMemEval score makes it hard to compare directly. Best suited for autonomous agent architectures where the memory system needs to evolve without human intervention.
Full comparisonSuperMemory
Best for: Quick RAG-based memory.
SuperMemory wraps a straightforward RAG pipeline with a clean API. At 81.6% on LongMemEval, it trails the top three but offers the fastest time-to-value for developers who just need “search over past conversations.” Free tier available with self-hosting option.
Full comparisonCognee
Best for: Enterprise data integration (30+ connectors).
Cognee differentiates with 30+ data connectors — pull memory from Slack, Notion, Google Drive, databases, and more. Enterprise pricing reaches $1,970/month, reflecting its positioning as a data integration platform. No published LongMemEval score. Best for organizations that need to unify memory across many data sources.
Full comparisonLangMem
Best for: LangGraph users needing simple memory.
LangMem is a lightweight memory module built specifically for the LangGraph ecosystem. Free and MIT-licensed, it provides basic memory primitives — store, retrieve, forget — rather than a complete system. The right choice if you are already deep in LangChain and want to add memory without leaving the ecosystem.
Full comparisonHindsight
Best for: Research and experimentation.
Hindsight takes a multi-strategy approach, letting you swap between different retrieval methods. Its 91.4% LongMemEval score is strong, and the architecture is well-suited for researchers comparing memory strategies. Newer and less battle-tested than the top three, but worth watching.
Full Comparison Table
All eight frameworks side by side. Scroll horizontally on mobile.
| Framework | LongMemEval | Pricing | Local | License | Best For |
|---|---|---|---|---|---|
| MemPalace | 96.6% | Free | Yes | MIT | Developers who want accuracy + privacy |
| Zep / Graphiti | ~85% | $0 - $475/mo | Self-host | Apache 2.0 | Apps needing temporal reasoning |
| Mem0 | ~85% | $19 - $249/mo | Open-source only | Apache 2.0 | Enterprise teams wanting managed service |
| Letta (MemGPT) | Not published | $0 - $249/mo | Self-host | Apache 2.0 | Autonomous agents with self-editing memory |
| SuperMemory | 81.6% | Free tier | Self-host | MIT | Quick RAG-based memory |
| Cognee | Not published | $0 - $1,970/mo | Self-host | Apache 2.0 | Enterprise data integration (30+ connectors) |
| LangMem | Not published | Free | Yes | MIT | LangGraph users needing simple memory |
| Hindsight | 91.4% | Free tier | Self-host | MIT | Research and experimentation |
How to Choose the Right Framework
Skip the analysis paralysis. Match your primary requirement to the right tool:
If… You want free + local + highest accuracy
MemPalace
96.6% raw accuracy, MIT license, runs entirely on your machine with zero API keys. Install in 3 commands.
If… You need enterprise support and managed cloud
Mem0 or Cognee
Mem0 offers YC backing and AWS partnership. Cognee has 30+ data connectors for enterprise pipelines.
If… You are building autonomous agents
Letta (MemGPT)
Self-editing memory lets agents decide what to remember and forget. Purpose-built for agentic workflows.
If… You already use LangGraph
LangMem
Native LangGraph integration. Lightweight building blocks for adding memory to existing LangChain pipelines.
If… You need temporal reasoning
Zep / Graphiti
Temporal knowledge graph tracks when facts were true. Best for apps where time context matters.
If… You want to experiment and compare strategies
Hindsight
Multi-strategy architecture (91.4% on LongMemEval) lets you swap retrieval methods easily.
Frequently Asked Questions
Which AI memory framework is best for free?
MemPalace and LangMem are both free and MIT-licensed. MemPalace provides a complete memory system with 96.6% raw accuracy on LongMemEval, 19 MCP tools, and local-first architecture. LangMem offers simpler building blocks within the LangGraph ecosystem. If you want a fully-featured solution at zero cost, MemPalace is the strongest option.
Which framework has the best benchmarks?
MemPalace leads with 96.6% rawon LongMemEval (100% in hybrid mode with Haiku reranking). Hindsight follows at 91.4%. Zep/Graphiti and Mem0 both land around 85%. Several frameworks — including Letta, Cognee, and LangMem — have not published official LongMemEval scores, making direct comparison difficult.
Can I switch between frameworks?
Most frameworks store data in standard formats (JSON, SQLite, vector embeddings), so migration is technically feasible. There are no universal migration tools yet, but you can typically export your conversation data and re-ingest it into a new framework through its API or MCP tools. The biggest friction point is usually differences in how each framework structures its knowledge graph.
Do I need a cloud account?
Only for managed cloud tiers. Mem0 Cloud, Zep Cloud, and Cognee Cloud require accounts and paid subscriptions. MemPalace, LangMem, SuperMemory (self-hosted), and the open-source versions of other frameworks all run locally with no cloud dependency.
Which framework works with Claude Code?
MemPalacehas native MCP integration with 19 purpose-built tools that work out of the box with Claude Code, Claude Desktop, and any MCP-compatible client. Mem0, Zep, and Letta also support MCP, but MemPalace's toolset covers the widest range of memory operations — from conversation storage to knowledge graph queries to memory analytics.
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