5 AI Agent Memory Systems Compared: Mem0, Zep, Letta, Supermemory, SuperLocalMemory (2026 Benchmark Data)

A factual comparison of the five most-referenced AI agent memory systems on architecture, LoCoMo benchmark scores, and EU AI Act compliance. Why This Post Exists Every comparison post I've read either reads like marketing for one system, or compares them on features without benchmark data. This is different: I'm the author of one of the systems (SuperLocalMemory), which means I have strong incentive to be honest — I can't be credibly wrong about the others without undermining my own credibility. All scores are from published papers or official documentation. I've noted where scores vary across sources. The Five Systems System Architecture Creator License Status Mem0 Cloud-hosted Mem0 AI ($24M funded) Open core Production Zep Cloud-hosted + self-host Getzep Apache 2.0 + Commercial Production Letta (MemGPT) Agent framework + LLM memory Letta AI Apache 2.0 Production Supermemory Cloud-hosted Open source project MIT Production SuperLocalMemory Local-first mathematical Independent research