LlamaIndex is an open-source AI development framework designed to help developers build intelligent applications, retrieval-augmented generation (RAG) systems, and AI agents that interact with private and external data sources.
Originally introduced as GPT Index in November 2022, LlamaIndex enables large language models (LLMs) to retrieve, understand, and use information from documents, databases, APIs, and enterprise knowledge bases. It helps developers connect AI models with relevant data without needing to train a new language model from scratch.
LlamaIndex supports Python and TypeScript development and provides flexible components for data ingestion, indexing, retrieval, query processing, agent orchestration, and application evaluation.
1. Retrieval-Augmented Generation (RAG)
Build AI applications that retrieve relevant information from external knowledge sources before generating answers. This supports context-aware responses grounded in documents and business data.
2. AI Agents and Workflows
Create intelligent AI agents capable of using external tools, completing multi-step tasks, maintaining state, and executing automated workflows. LlamaIndex supports event-driven orchestration, branching logic, and human-in-the-loop processes.
3. Data Ingestion and Connectors
Connect LLM applications with documents, databases, cloud storage systems, APIs, and other data sources through an extensible integration ecosystem.
4. Document Parsing and Understanding
Integrate with LlamaParse, LlamaIndex's hosted document-processing platform, to convert PDFs, scanned files, spreadsheets, presentations, tables, charts, and other complex documents into structured, AI-ready information.
5. Vector Indexing and Semantic Retrieval
Create searchable indexes using embedding models and vector databases. Developers can implement semantic search, document retrieval, and context-aware question answering.
6. Query Engines and Chatbots
Develop conversational AI assistants, internal knowledge assistants, document-based chatbots, and question-answering systems powered by organizational information.
7. Structured Data Extraction
Extract structured information from documents and unstructured content, including schema-based JSON output through compatible LlamaParse services.
8. Multiple LLM Integrations
Integrate with supported commercial and open-source language models, embedding providers, vector databases, and third-party development tools.
9. Multimodal AI Applications
Build applications that work with combinations of text, images, tables, charts, and other supported content types.
10. Evaluation and Observability
Test retrieval quality, evaluate AI application behavior, and integrate tracing and monitoring capabilities to improve reliability.
LlamaIndex is particularly suitable for AI engineers, Python and TypeScript developers, machine learning practitioners, startups, enterprise development teams, and organizations building applications that need access to external or proprietary information.
The core LlamaIndex framework is free and open-source. LlamaParse, its commercial hosted document-processing platform, offers a free tier and paid plans. External LLM APIs, hosting, and other infrastructure may incur additional charges.
LlamaIndex is primarily a developer framework rather than a ready-made consumer chatbot application.
Software pricing, API capabilities, and feature tiers for LlamaIndex are periodically audited. If you notice any outdated specifications, please notify our editorial staff via our Contact Page.