Letta
agent-frameworks
Stateful AI agents with long-term memory (formerly MemGPT).
Pricing
Free plan
Rating
—
Votes
0
Head-to-head comparison
Letta vs Semantic Kernel
Compare Letta and Semantic Kernel side by side across pricing, features, ratings, pros, cons, best-fit use cases, and alternatives.
Semantic Kernel
agent-frameworks
Microsoft's enterprise SDK for orchestrating LLMs, plugins, and agents.
Pricing
Free
Rating
—
Votes
0
Feature comparison
Feature
Letta
Semantic Kernel
Category
agent-frameworks
agent-frameworks
Pricing
Free plan
Free
Free plan
API access
Mobile app
Browser extension
Team collaboration
Custom training
Self-hosted option
Offline mode
Multi-language support
Letta pros and cons
Purpose-built for the agent memory problem
Strong research pedigree (MemGPT paper)
OS-style tiered memory persists across sessions
Open-source core, free to self-host
Narrower than general agent frameworks
Often used alongside other tooling, not a full stack
Renamed from MemGPT, some older docs use old name
Semantic Kernel pros and cons
First-class C#/.NET support, rare among AI frameworks
Free and open source
Enterprise features: type safety, DI, telemetry
Multi-language (C#, Python, Java)
Strategic focus shifting to Microsoft Agent Framework
Concepts like planners have changed across versions
Python support historically trailed .NET
Which one should you choose?
Best overall signal
Semantic Kernel
Selected using Toolglade popularity signals such as views and votes.
Best value signal
Letta
Selected using free-plan availability and engagement signals.
Best for
Letta
- developers
- Teams that need persistent agent memory
- Builders of long-running assistants
- Researchers exploring stateful agents
Semantic Kernel
- enterprise .NET AI apps
- plugin and tool orchestration
- LLM integration in existing systems
- agent building on Microsoft stacks
- Enterprise .NET development teams
FAQ
Is Letta better than Semantic Kernel?
It depends on your use case. Compare category fit, pricing, feature availability, and ratings before choosing.
Which tool has a free plan?
Letta and Semantic Kernel offer a free plan based on current Toolglade data.
Where can I find alternatives?
View Letta alternatives or view Semantic Kernel alternatives.