Open WebUI vs LibreChat

Architecture comparison 2 projects Built from source-audited deep dives

Both are self-hosted chat UIs for many model providers. Open WebUI is a Python FastAPI + SvelteKit app shipped as one image that runs offline with Ollama and SQLite by default; LibreChat is a Node/Express + React app built around MongoDB, with RAG, search and tracing as optional sidecar services.

Open WebUI LibreChat

Open WebUI: Python · NOASSERTION
LibreChat: TypeScript · MIT
Updated: 2026-09-25

Which one should you pick?

Pick Open WebUI if…

You want one container that works fully offline with local models via Ollama
You prefer SQLite by default with an upgrade path to PostgreSQL
You want built-in RAG with a choice of nine vector databases

Pick LibreChat if…

Your team is more at home in Node.js/TypeScript than Python
You want many auth strategies (LDAP, SAML, OAuth providers) through one Passport layer
You want agents calling external tools over MCP and MIT licensing

Side by side

Attribute	Open WebUI	LibreChat
Written in	Python Svelte JavaScript	TypeScript JavaScript
License	NOASSERTION	MIT
Frontend	SvelteKit Svelte Vite Tailwind CSS Socket.IO	React Vite Tailwind CSS
Backend & APIs	Python FastAPIpython-socketioLangChainAPScheduler	Express Model Context Protocol
Data & persistence	SQLAlchemy SQLite PostgreSQL Redis Chroma	MongoDB Redis pgvector
Infrastructure & deploy	Docker GitHub Actions Ollama	Docker Go GitHub Actions
Key decisions	One Docker image bundles the built frontend and the Python backend SQLite by default, PostgreSQL for scale, same SQLAlchemy models Nine vector databases sit behind one RAG interface	MongoDB, not PostgreSQL, is the single source of truth Client, backend, and shared logic are npm workspaces, not separate repos RAG and search run as optional sidecar services
Audited	0a7c158 · 2026-09-17	12d7890 · 2026-09-17

How they differ

Two different stacks

Open WebUI is Python on the server (FastAPI, python-socketio, APScheduler) and SvelteKit in the browser, compiled together into a single Docker image. LibreChat is an npm workspace monorepo: an Express API, a Vite-built React client and shared packages for data schemas and the API client.

Data and retrieval

Open WebUI keeps app data in SQLite or PostgreSQL through SQLAlchemy, and its RAG pipeline puts embeddings in Chroma by default with Qdrant, Milvus, Pinecone, OpenSearch, Elasticsearch, Weaviate or pgvector as options. LibreChat treats MongoDB as the single source of truth and runs retrieval and search as sidecars: a RAG API backed by pgvector and Meilisearch for message search.

Models and tools

Both call providers through their official SDKs rather than one abstraction. Open WebUI connects to Ollama and any OpenAI-compatible API, plus Anthropic and Google SDKs. LibreChat supports OpenAI, Anthropic, Azure, Bedrock and Vertex, and its agents call external tools through MCP. LibreChat also ships a small Go service that relays OpenTelemetry traces to Langfuse.

Architecture diagrams

Open WebUI Open SVG

LibreChat Open SVG

Frequently asked questions

Does Open WebUI or LibreChat use PostgreSQL?

Open WebUI uses SQLite by default and supports PostgreSQL through the same SQLAlchemy models. LibreChat stores conversations, users and agents in MongoDB; PostgreSQL only appears as the pgvector store for its optional RAG API.

Which one is easier to self-host?

Open WebUI ships the built frontend and Python backend in one Docker image with no required external services. LibreChat's docker-compose.yml runs the API with MongoDB, Meilisearch and optional pgvector and RAG API containers.

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