Agent Framework

Google ADK vs Haystack: Which is Better in 2026?

Choosing between Google ADK and Haystack? Both are popular agent framework tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.

Quick verdict

Both Google ADK and Haystack are strong agent framework choices. The right pick comes down to your specific feature needs, existing stack, and team preferences. In our catalog, Google ADK rates slightly higher (4.4 vs 4.2 out of 5).

Google ADK vs Haystack — Side by Side

Google ADKHaystack
CategoryAgent FrameworkAgent Framework
PricingFreeFree
Starting priceFree tier availableFree tier available
Free tier
Rating4.44.2
Best forAgent Framework — ai, llmAgent Framework — rag, retrieval

Pros & Cons

Google ADK
Google ADK
  • Deep GCP / Vertex AI integration
  • Strong multi-agent support
  • Model-agnostic via LiteLLM
  • Backed by Google
  • Best value tied to Google Cloud
  • Younger ecosystem than LangChain
Haystack
Haystack
  • Best retrieval abstractions of the group
  • Pipelines are explicit and debuggable
  • Production-minded from the start
  • Smaller ecosystem than LangChain
  • Pipeline model takes a while to click

Key Features Compared

Google ADK

  • Multi-agent orchestration
  • Gemini-optimized, model-agnostic (LiteLLM)
  • Built-in evaluation
  • Tooling & code execution
  • Python & Java

Haystack

  • Composable pipelines
  • Retrieval and RAG components
  • Agent and tool support
  • Evaluation tooling

Choose Google ADK if…

  • You want a free tier to validate before paying.
  • Deep GCP / Vertex AI integration
  • Strong multi-agent support
  • Model-agnostic via LiteLLM
Google ADK review & pricing

Choose Haystack if…

  • You want a free tier to validate before paying.
  • Best retrieval abstractions of the group
  • Pipelines are explicit and debuggable
  • Production-minded from the start
Haystack review & pricing

Frequently Asked Questions

Is Google ADK better than Haystack?⌄

Both Google ADK and Haystack are strong agent framework choices. The right pick comes down to your specific feature needs, existing stack, and team preferences. In our catalog, Google ADK rates slightly higher (4.4 vs 4.2 out of 5).

What is the difference between Google ADK and Haystack?⌄

Google ADK — Google's open-source Agent Development Kit — multi-agent systems optimized for Gemini and Vertex AI, model-agnostic via LiteLLM. Haystack — deepset's pipeline framework for RAG and agents, strongest on retrieval. Both are agent framework tools; the comparison table above breaks down pricing, free tiers, and what each is best for.

Google ADK vs Haystack: which is cheaper?⌄

Google ADK pricing: Free. Haystack pricing: Free. Confirm current pricing on each tool's official site, as plans change.

Which is rated higher, Google ADK or Haystack?⌄

In our catalog, Google ADK rates 4.4 out of 5 and Haystack rates 4.2 out of 5, so Google ADK has a slight edge on reviews.

See more options in our guide to the best agent framework tools for startups.

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