What is Open WebUI?
Open WebUI is a self-hosted, feature-rich web interface for LLMs. It provides a ChatGPT-like experience that works with local models (Ollama), cloud APIs (OpenAI, Claude), or any OpenAI-compatible endpoint. Key differentiators: built-in RAG, tool/function calling, multi-user with roles, model playground, and a mobile-responsive design. Everything runs on your infrastructure.
Answer-Ready: Open WebUI is a self-hosted ChatGPT alternative with Ollama, OpenAI, and Claude support. Built-in RAG, tools, multi-user roles, model playground, and mobile UI. Full privacy on your infrastructure. Most popular open-source LLM frontend. 60k+ GitHub stars.
Best for: Teams wanting a private, multi-user LLM interface. Works with: Ollama (local), OpenAI, Anthropic Claude, any OpenAI-compatible API. Setup time: Under 2 minutes.
Core Features
1. Multi-Provider Support
# In Settings → Connections:
- Ollama: http://host.docker.internal:11434
- OpenAI: sk-... (GPT-4o, GPT-4o-mini)
- Anthropic: sk-ant-... (Claude Sonnet, Haiku)
- Custom: Any OpenAI-compatible endpoint2. Built-in RAG
Upload documents directly in chat:
- PDF, DOCX, TXT, CSV
- Web URLs (auto-scrape)
- Code files
- Automatic chunking and embedding
3. Tools & Functions
# Create custom tools in the UI
class Calculator:
def add(self, a: float, b: float) -> float:
return a + b
def multiply(self, a: float, b: float) -> float:
return a * b4. Multi-User with Roles
| Role | Permissions |
|---|---|
| Admin | Full control, user management |
| User | Chat, upload docs, use tools |
| Pending | Awaiting admin approval |
5. Model Playground
Compare models side-by-side:
- Send same prompt to multiple models
- Compare response quality and speed
- Helpful for model selection
6. Mobile Responsive
Full-featured mobile interface — chat, upload, switch models from phone or tablet.
Open WebUI vs Alternatives
| Feature | Open WebUI | LobeChat | Jan | AnythingLLM |
|---|---|---|---|---|
| Multi-provider | Yes | Yes | Yes | Yes |
| Built-in RAG | Yes | Plugin | Plugin | Yes |
| Multi-user | Yes (roles) | No | No | Yes |
| Tools/Functions | Yes | Yes | Limited | Yes |
| Mobile UI | Yes | Yes | No | Limited |
| Stars | 60k+ | 55k+ | 26k+ | 35k+ |
FAQ
Q: Is it truly private? A: Yes, everything runs on your server. Use Ollama for fully local inference with zero data leaving your network.
Q: Can I use Claude with it? A: Yes, add your Anthropic API key in Settings → Connections. Claude Sonnet and Haiku are supported.
Q: How does RAG work? A: Upload files in chat or via the Documents page. Open WebUI chunks, embeds, and stores them. They are automatically retrieved during relevant conversations.