Haystack by deepset is an open-source framework for building production-ready RAG pipelines, semantic search, and question answering systems. It provides modular components for document processing, retrieval, and generation with support for multiple LLM providers and vector stores.
Vectara is a RAG-as-a-service platform that provides end-to-end retrieval-augmented generation through a single API. It handles document ingestion, chunking, embedding, retrieval, reranking, and generation—with built-in hallucination detection and citation extraction—without requiring developers to manage any RAG infrastructure.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Choose Haystack if you wantChoose if you want
Choose Vectara if you wantChoose if you want
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 500+ models through one gateway.