Dify
Leading#2 in Open sourcehigh confidence
Open-source LLM app platform with a built-in knowledge base, document ingestion, and RAG pipeline behind a full UI; the highest-starred option here (~150k stars).Our read
Why it ranks #2
The existing GitHub source records roughly 150k stars, the largest raw star signal in this file, and Dify is widely compared as a full open-source alternative to commercial LLM app builders.Here is the catch
Self-hosting involves multiple services and nontrivial upgrades
Complex workflows can become difficult to version and debug
Cloud and model usage limits add cost beyond the open-source license
Does this well
Full UI makes RAG application building accessible beyond developers
Combines ingestion, workflows, model access, and deployment in one platform
Large and active open-source community
Pricing
Checked by hand on 2026-07-23. Prices in this category change often — if this looks wrong, it probably is.
Key features
Visual LLM workflow builderBuilt-in knowledge bases and retrievalPrompt and agent orchestrationModel management and observability
Sources we read
Quick facts
More in this area
The rest of the Open source column.- 1LangChainThe de-facto framework for building RAG and knowledge-base apps — chains, agents, and connectors to every model and vector store. The category's recognized leader (~142k stars).
- 3RAGFlowDedicated open-source RAG engine with deep document parsing, knowledge-base management, and a zero-code web UI (~86k stars).
- 4AnythingLLMAll-in-one desktop/self-hosted app that turns your documents into a private chat knowledge base out of the box (~64k stars).
- 5LlamaIndexThe data framework for indexing and querying your private content; the reference toolkit for document-QA knowledge bases (~51k stars).
- 6QuivrOpinionated RAG 'second brain' you can plug into your apps to store and query your documents (~39k stars).
- 7KhojSelf-hostable AI second brain that searches and chats across your notes, docs, and PDFs (~36k stars).