LangGraph vs Haystack
Stateful graph workflows vs. production search pipelines. LangGraph for branching agent logic, Haystack for retrieval at scale.
LangGraph
Stateful multi-agent orchestration built on LangChain
View full detailsLangGraph and Haystack solve different problems that happen to share the letters 'LLM pipeline', so the first question is which problem you actually have. LangGraph, from the LangChain team, is for building stateful agent applications: you define a graph of steps with branching, loops, persistent state, and human-approval checkpoints. It shines when an LLM needs to decide what to do next, possibly many times, over a long-running task.
Haystack, from deepset, comes from the search world. It is a mature framework for production retrieval and RAG pipelines (document ingestion, retrievers, rankers, readers) with a reputation for clean abstractions and operational solidity, and it predates the current agent wave. It has agent features too, but pipelines are its soul. If your system mostly retrieves and answers, Haystack fits; if it mostly decides and acts, LangGraph fits.
| LangGraph | Haystack | |
|---|---|---|
| Best for | Stateful agents with branching and loops | Production RAG and search pipelines |
| Core abstraction | Graph of nodes with persistent state | Pipeline of composable components |
| Backed by | LangChain team | deepset, with enterprise offering |
| Human in the loop | Built-in checkpoints and interrupts | Possible, not the core design |
| Retrieval depth | Delegated to other libraries | Mature retrievers, rankers, converters built in |
| Maturity style | Newer, fast-moving agent focus | Older, search-rooted, operationally proven |
| Learning curve | Graph thinking takes adjustment | Straightforward if you know pipelines |
Editor rating is our overall editorial judgment of the tool, out of 5. It is not a test score and not a user-review average. Ratings have not been re-scored since the tool was listed here. Each tool page says why.
Classify your system: answering or acting
Sketch your application as a flow. If it is mostly 'question in, retrieve documents, answer out', even with reranking and filters, that is a pipeline, and Haystack was built for it. If the flow has decision points, retries, loops, or tool calls chosen at runtime, that is agent territory and LangGraph's home.
Decide how much state you need to keep
LangGraph's defining feature is durable state: conversations that pause for human approval, resume after failures, and branch on conditions. If your system needs none of that, because each request is independent, you would be paying LangGraph's complexity tax for capabilities a stateless Haystack pipeline does not need.
Consider your existing stack and team
Teams already invested in LangChain get LangGraph almost for free conceptually, plus LangSmith observability. Teams running search infrastructure, or wanting deepset's enterprise support, will find Haystack's component model and deployment story more familiar. Adopting the framework that matches your existing tooling reduces real risk.
Prototype the riskiest part, not the easy part
Build the piece you are least sure of first: the trickiest retrieval case in Haystack, or the most complex decision loop in LangGraph. A week on the hard part tells you more than a month on hello-world demos. And note that some systems legitimately use both: a LangGraph agent calling a Haystack pipeline as a tool.
When to pick LangGraph
Pick LangGraph if you are building agents that make decisions, loop, pause for human approval, or carry state across long-running tasks.
When to pick Haystack
Pick Haystack if you are building production retrieval or RAG systems where pipeline quality, mature components, and operational stability matter most.
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Frequently asked questions
How are these comparisons built?
From the same editorial data we maintain for every tool: category, pricing, strengths and best-fit users. When an editor has written a verdict for a pair, it appears here too; otherwise the table is generated directly from the tool data.
Can I compare any two tools?
Yes. Pick any two from the selector above. The side-by-side view is generated from our tool catalog on the spot.
How current is the pricing?
Pricing reflects our last editorial review of each tool. Vendors change plans often, so confirm on the vendor's site before you buy.