Introduction
Open WebUI is an open-source, self-hosted chat front-end for LLMs that enables teams to interact with locally or remotely hosted models through a clean, intuitive interface—with full control over data, privacy, and customization. Open WebUI is purpose-built for developers and teams working with models served via Ollama, vLLM, or LM Studio, offering both lightweight deployment and powerful functionality out of the box. At Cake, Open WebUI serves as a trusted layer for interacting with internal models, testing prompt flows, and running human-in-the-loop evaluations securely within infrastructure boundaries.
Key Benefits of Using Open WebUI include:
Model-Agnostic Frontend: Works seamlessly with LLM models served by vLLM, Ollama, Triton, model proxies like LiteLLM or custom APIs—making it a flexible tool for testing any model served within Cake’s stack or by external inference vendor APIs.
Fully Self-Hosted: Can be deployed securely behind Cake’s firewalls or on developer machines, ensuring zero data leaves internal systems.
Multi-Model and Multi-Session Support: Enables switching between models and running independent chat sessions for A/B testing or evaluation.
Rich Chat Features: Includes token usage display, markdown rendering, conversation history, system prompt injection, and copy/export tools for responses.
Lightweight and Container-Ready: Easily deployable via Docker, Kubernetes, or local binaries for rapid testing or team-wide usage.
Use Cases
Open WebUI is used for:
LLM Prototyping and Testing: Providing a human-readable chat interface for testing new model versions, fine-tuned checkpoints, or system prompts in real time.
Evaluation and Red Teaming: Allowing product and safety teams to interact with models for behavioral testing, edge case discovery, and qualitative feedback collection.
Prompt Design and Debugging: Serving as a visual sandbox for comparing prompt versions, analyzing system message effects, or testing few-shot chains.
Developer Access to Local Models: Giving engineers an interface to test Ollama- or vLLM-hosted models without needing to build custom UIs.
Open WebUI is often deployed alongside model proxies and server like LiteLLM, vLLM, and Ollama. and is complemented by tools like LangChain, LangFuse, and TrustCall for deeper integration and monitoring. Open WebUI empowers teams with a private, customizable, and developer-friendly interface for interacting with local LLMs—accelerating iteration, enhancing visibility, and ensuring full control over model usage and behavior.