Updated August 2026
Benchmarks Cited, Sources Named

CogmemAi vs Mem0 vs Zep

Three serious Ai memory layers, compared honestly. Each is the right choice for somebody, and this page says for whom. Every benchmark number below is labeled with who measured it.

The Benchmark Picture

LongMemEval (500 questions, ICLR 2025) is the hardest widely used test of long-term Ai memory: multi-session reasoning, temporal reasoning, knowledge updates, and abstention.

CogmemAi: 95.10%

The top published LongMemEval score, above the human baseline of 87.9%, with a 100% retrieval hit rate and 91% on LoCoMo. Self-published, August 2026; methodology on the developer page.

Mem0: 94.4%

Self-reported in Mem0's 2026 research report, alongside 92.5% on LoCoMo, with strong token-efficiency results (roughly 7,000 tokens per call against 25,000+ for full-context approaches).

Zep: 71.2%

Measured in independent 2026 testing of Zep's Graphiti engine (63.8% on the temporal retrieval sub-task with GPT-4o). Zep's strength is its temporal knowledge graph rather than raw recall score.

Self-reported numbers are exactly that: each vendor, including us, runs its own harness. Where an independent measurement exists we cite it. Run your own evaluation before you commit; our free tier makes that easy.

Feature by Feature

Capability CogmemAi Mem0 Zep
LongMemEval score 95.10% (self-published) 94.4% (self-reported) 71.2% (independent)
Autonomous capture (saves without the Ai choosing to) Yes No No
Contradiction detection Yes, flagged at recall Consolidation on Pro tier Graph fact invalidation
Behavioral rules the Ai must follow Mandatory rules + auto-skills No No
Temporal knowledge graph Auto-linking graph Graph memory ($249/mo tier) Yes, core strength (Graphiti)
Encryption of memory content Quantum-safe at rest Standard Standard
MCP zero-install remote endpoint Yes MCP via OpenMemory MCP available
One memory across editors, agents, and devices Yes, that is the product Per-app by design Per-app by design
Team memory with author attribution Yes Projects Groups
Open source Clients and SDKs only; engine is proprietary Yes (Apache 2.0 core) Graphiti engine is open
On-premises option Edge, by contract Enterprise tier Enterprise tier
Entry price Free; paid from $3.99/mo Free; paid from $19/mo (graph at $249/mo) Free; Flex at $25/mo

The Honest Recommendation

Choose Mem0 if…

You want an open-source library you can embed, fork, and modify freely inside your own application, and you are comfortable operating it yourself. It is well funded, well documented, and the community is large.

Choose Zep if…

Temporal graph queries are your core need: you want to ask how facts about an entity changed over time, and $25/mo for a full graph engine is the budget. Graphiti is genuinely good at that job.

Choose CogmemAi if…

You want the highest published recall, memory that follows you across every tool rather than living inside one app, capture that happens even when the Ai forgets to save, encrypted content, and an on-premises path for the day compliance demands it.

Run the Comparison Yourself

A free key takes sixty seconds and no card. Point your own evaluation at it.