Agents & frameworks · A-tier

LlamaIndex

Open-source framework for retrieval and document agents. The library is free; LlamaCloud is paid.

Open LlamaIndex Best AI agent frameworks

Best for

Document Q&A and agents that have to cite your own files.

What it is

LlamaIndex is an open-source framework focused on retrieval over your documents and on agents that query them. It started as GPT Index. The library is free. LlamaCloud is the hosted parsing and index product.

open-sourceragdocumentsAgents & frameworks

Score breakdown

Capability 40%84
Ease 25%70
Value 20%88
Momentum 15%78

Pricing

Free

Starting price: $0

The framework is open source. LlamaCloud and enterprise indexes are priced separately. Check the site.

Dates

Released 2022 (year precision).

Added to StackPick 14 Oct 2026.

Alternatives

A-tier · 83

LangChain

Application code that needs tools, retrieval, and a large example ecosystem.

A-tier · 84

Mastra

TypeScript teams who want agents, workflows, and evals in one library.

A-tier · 81

Dify

Teams who want a visual LLM app builder they can self-host.

Comparisons

vs LangChain

Questions

What is LlamaIndex best for?

Document Q&A and agents that have to cite your own files.

How much does LlamaIndex cost?

Free. Starting price: $0. The framework is open source. LlamaCloud and enterprise indexes are priced separately. Check the site.

What are alternatives to LlamaIndex?

LangChain, Mastra, Dify are the alternatives we file next to it. Open a comparison when one exists.