LlamaIndex

LlamaIndex is an open-source data framework for connecting LLMs to your data via ingestion, indexing, and retrieval, specializing in RAG and knowledge agents. Its managed LlamaCloud platform adds high-quality document parsing (LlamaParse) and managed indexing and extraction. The frameworks are free; LlamaCloud uses credit-based usage billing.

LlamaIndex is an open-source data framework focused on the retrieval and knowledge side of LLM applications. It provides tools to ingest data from many sources, index it (via vector, keyword, and other structures), and retrieve relevant context to feed into LLMs, making it a natural fit for retrieval-augmented generation and document-heavy question answering. It has expanded toward agentic workflows, offering building blocks for knowledge agents that reason over enterprise data. Alongside the open-source Python and TypeScript frameworks, the company offers LlamaCloud, a managed platform whose standout component is LlamaParse, a high-quality document parsing service for extracting structured content from complex PDFs, spreadsheets, and other formats, plus managed indexing and extraction. This addresses one of the hardest, least glamorous parts of production RAG: reliably getting clean data out of messy documents. The frameworks are free and open source (MIT), while LlamaCloud is the commercial offering with a credit-based, usage-metered model and a free tier. LlamaIndex competes with LangChain on the framework side and differentiates by concentrating on data ingestion, parsing, and retrieval quality for enterprise knowledge use cases.