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Machine Learning · head to head

Semantic Kernel vs Vellum

Semantic Kernel logo

Semantic Kernel

Machine Learning

Model-agnostic SDK for AI orchestration

From
Free
Free plan
Yes
Full reviewWebsite
Vellum logo

Vellum

AI

Personalized AI assistant with persistent memory and autonomous action-taking

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Semantic Kernel steep learning curve for advanced features; Vellum pricing varies significantly by computational tier, making budget planning difficult
  • They diverge on capability: Semantic Kernel covers Multi-model support, Vellum covers Persistent AI identity.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Semantic Kernel and Vellum actually diverge.

Attributes where Semantic Kernel and Vellum differ
AttributeSemantic KernelVellum
Pricing modelOpen source, no pricingFreemium with paid plans and pay-as-you-go credits
PlatformsPython, .NET, JavaWeb, macOS, iOS, Slack, Telegram, Terminal
CategoryMachine LearningAI

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Semantic Kernel

  • Multi-model support
  • Agent framework
  • Multi-agent systems
  • Plugin ecosystem
  • Vector database integration
  • Multimodal support
  • Local model support
  • Enterprise observability

Only in Vellum

  • Persistent AI identity
  • Long-term memory
  • Email automation
  • Calendar management
  • Autonomous task execution
  • Multi-device synchronization
  • Custom plugins
  • Open-source deployment

What people use each for

The jobs each tool is most often brought in to do.

Semantic Kernel

  • Building enterprise AI applications with LLM integrationnot Vellum
  • Creating multi-agent systems for complex workflowsnot Vellum
  • Developing AI-powered chatbots and assistantsnot Vellum
  • Implementing RAG systems with vector databasesnot Vellum

Vellum

  • Personal productivity automation across email and calendarnot Semantic Kernel
  • CRM updates and pipeline managementnot Semantic Kernel
  • Expense report generation and managementnot Semantic Kernel
  • Document drafting and content creationnot Semantic Kernel
  • Meeting scheduling and calendar coordinationnot Semantic Kernel

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Semantic Kernel

  • Steep learning curve for advanced features
  • Documentation focuses on Azure cloud services
  • Configuration complexity for multi-model scenarios
  • Requires understanding of AI/LLM concepts

Vellum

  • Pricing varies significantly by computational tier, making budget planning difficult
  • Requires explicit permission for sensitive actions, limiting autonomy
  • Self-hosting option may intimidate non-technical users
  • Learning curve to develop customizations with plugins

Pricing, plan by plan

Semantic Kernel

Free
  • Open SourceFree
    • MIT license
    • Full framework access
    • All language SDKs

Vellum

Free
  • FreeFree
    • Starter credits included
    • Basic features
  • Mighty$30/month
    • 1 vCPU, 2 GiB RAM
    • 10 GB storage
    • Included usage allowance
  • Super$100/month
    • 2.5 vCPU, 5 GiB RAM
    • 30 GB storage
    • Assistant email and subdomain
  • Ultra$200/month
    • 4 vCPU, 8 GiB RAM
    • 60 GB storage
    • Assistant email and subdomain

Which should you pick?

Choose Semantic Kernel if

  • You need multi-model support.
  • You want to start without paying.
  • You work on Python, .NET, Java.
  • You also want agent framework.
Semantic Kernel review

Choose Vellum if

  • You need persistent ai identity.
  • You want to start without paying.
  • You work on Web, macOS, iOS, Slack, Telegram, Terminal.
  • You also want long-term memory.
Vellum review

Questions people ask

Is Semantic Kernel or Vellum better?
Neither clearly leads. Semantic Kernel starts at Free and Vellum at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Semantic Kernel or Vellum?
Semantic Kernel starts at Free and Vellum at Free.
Does Semantic Kernel or Vellum run on more platforms?
Semantic Kernel runs on Python, .NET, Java. Vellum runs on Web, macOS, iOS, Slack, Telegram, Terminal.
Can I use Semantic Kernel for free?
Both have a free tier, so you can try either at no cost before committing.
What is Semantic Kernel best used for?
Semantic Kernel is most often used for building enterprise ai applications with llm integration, creating multi-agent systems for complex workflows, developing ai-powered chatbots and assistants, implementing rag systems with vector databases. Of those, building enterprise ai applications with llm integration and creating multi-agent systems for complex workflows are not what Vellum is typically brought in for.
What can Semantic Kernel do that Vellum cannot?
Semantic Kernel covers Multi-model support, Agent framework, Multi-agent systems, Plugin ecosystem. Vellum covers Persistent AI identity, Long-term memory, Email automation, Calendar management.

Answered from the vendors’ own pages

Semantic Kernel: What LLM providers does Semantic Kernel support?

Semantic Kernel supports OpenAI, Azure OpenAI, Hugging Face, Nvidia, and other providers through extensible model implementations.

Source
Vellum: How does Vellum protect my data privacy?

Vellum uses permission-based controls requiring explicit approval for sensitive actions. Data is encrypted and the option for self-hosting provides complete data control. Open-source deployment option allows hosting on your own infrastructure.

Source
Semantic Kernel: Can I run Semantic Kernel locally?

Yes. Semantic Kernel supports local models through Ollama, LMStudio, and ONNX for complete data control and offline operation.

Source
Vellum: Can I use Vellum for business team collaboration?

Vellum is primarily designed as a personal assistant with persistent identity. For team collaboration, platforms like Lindy offer better multi-user features with shared credit pools and Slack workspace integration.

Source
Semantic Kernel: Is Semantic Kernel free?

Yes. Semantic Kernel is MIT-licensed open source and completely free. You only pay for external LLM APIs you use.

Source
Vellum: What does the free tier include?

Vellum offers free starter credits to begin using the platform. Beyond that, it operates on a pay-as-you-go credit model with paid tiers starting at $30/month for increased computational resources and bundled credits.

Source
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