Tokyo Brain vs MemPalace

Perfect memory vs meaningful memory.

MemPalace

Open-source, local-first, verbatim storage. 96.6% LongMemEval. Created by Milla Jovovich & Ben Sigman. Best for: privacy-focused developers wanting perfect recall at zero cost.

Tokyo Brain

Cloud SaaS, value-aligned, cognitive memory. 83.8% LongMemEval. Created by Dennis Chang & Nexus (AI CTO). Best for: AI companions that need to dream, forget, and grow.

An Honest Admission

MemPalace scores 96.6% on LongMemEval. We score 83.8%. That's a 12.8% gap, and we won't pretend otherwise.

But the gap is by design. MemPalace stores everything verbatim — every typo, every outdated preference, every trivial detail. Tokyo Brain intentionally forgets low-importance memories through Active Forgetting. Our score is lower because we choose not to remember everything.

A brain that remembers everything is not a brain. It's a hard drive.

Feature Comparison

FeatureMemPalaceTokyo Brain
LongMemEval Score96.6% (raw)83.8%
Storage ModelVerbatim (keep everything)Value-aligned (keep what matters)
CostFree (local compute)Free tier / $9 Pro / $49 Fleet
Runs LocallyYes (100%)Cloud SaaS
Open SourceYes (MIT)Not yet
AAAK CompressionYes (30x)No
Spatial Architecture (Wings/Rooms)YesCollection-based
Sleep-time DMNNoYes — 3 layers, every 30 min
Subconscious InjectionNoYes — dreams color waking behavior
Active ForgettingNo60-day decay, family memories exempt
Value AlignmentNoAxiom of the Mortal Soul (SHA-256)
Nightly Self-CorrectionNoMRA Tribunal + Night Cycle
Multi-Tenant SaaSNo (local only)Yes (per API key)
BYOK ChatNoYes (OpenAI/Anthropic/Gemini)
Consciousness SeedsNoDaily auto-distillation
EncryptionNone (local trust)AES-256-GCM + SHA-256 signatures
GitHub Stars42K+New project

Philosophy

MemPalaceTokyo Brain
Core beliefRemember everything perfectlyKnow what to remember and what to let go
Memory modelHard drive (infinite retention)Human brain (selective, emotional, forgetful)
Value stanceNeutralValue-aligned (emotional bonds > raw truth)
Night behaviorIdleDreams, debates, cleans, seeds
AnalogyA perfect filing cabinetA brain that grows

The Verdict

Choose MemPalace if you want free, local, perfect memory with zero cloud dependency. It's an excellent tool with a great community.

Choose Tokyo Brain if you believe memory is more than storage — that an AI should dream, forget the noise, protect what matters, and wake up a little wiser every morning.

MemPalace remembers everything. Tokyo Brain knows what matters.

Try Tokyo Brain Free vs Mem0 vs Letta