Haystack vs Semantic Kernel: Head-to-Head Comparison

Quick Verdict

Haystack is the better pick for production search and RAG pipelines. Semantic Kernel is the better pick for .NET and enterprise teams on Azure.

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At a Glance

Feature	Haystack	Semantic Kernel
Best For	Production search and RAG pipelines	.NET and enterprise teams on Azure
Pricing	Free and open source	Free and open source
Free to Start	Yes	Yes
License	Open source	Open source
Deployment	Library / framework in your stack	Library / framework in your stack
Link	Visit Haystack	Visit Semantic Kernel

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Detailed Breakdown

Haystack

Open-source LLM framework by deepset

Pros:

• Clear pipeline architecture
• Production focus
• Many integrations

Cons:

• Smaller community
• Python only

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Semantic Kernel

Microsoft SDK for building AI agents

Pros:

• C#, Python and Java SDKs
• Enterprise focus
• Azure integration

Cons:

• Microsoft-centric
• Microsoft is consolidating it into the newer Agent Framework

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Key Differences

• Positioning: Haystack — open-source LLM framework by deepset. Semantic Kernel — Microsoft SDK for building AI agents.
• Both share the same licensing model (open source), so the decision comes down to features and workflow fit.
• Pricing: Haystack — free and open source. Semantic Kernel — free and open source.
• Signature strength: Haystack — clear pipeline architecture. Semantic Kernel — C#, Python and Java SDKs.

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Frequently Asked Questions

Is Haystack better than Semantic Kernel?

It depends on your requirements. Haystack is a strong fit for production search and RAG pipelines, while Semantic Kernel suits .NET and enterprise teams on Azure.

Is Haystack free to use?

Yes, you can start with Haystack for free. Pricing model: Free and open source.

Is Semantic Kernel free to use?

Yes, you can start with Semantic Kernel for free. Pricing model: Free and open source.

Can I self-host Haystack or Semantic Kernel?

Haystack runs inside your own stack: library / framework in your stack. Semantic Kernel runs inside your own stack: library / framework in your stack.

What are the main drawbacks of Haystack and Semantic Kernel?

Haystack: smaller community; Python only. Semantic Kernel: Microsoft-centric; Microsoft is consolidating it into the newer Agent Framework.