Updated April 29, 2026
Open WebUI is the de-facto self-hosted AI chat platform — a feature-rich, extensible web UI that runs entirely offline and supports Ollama, OpenAI-compatible APIs, MCP servers, RAG with 9+ vector databases, voice I/O, and multi-user RBAC. 124K+ GitHub stars, 282M+ downloads.
Stack AI is a no-code platform for building AI workflows and applications. It provides a visual drag-and-drop interface for creating RAG pipelines, chatbots, document processing workflows, and AI agents. Stack AI connects to enterprise data sources and deploys as APIs or embeddable widgets.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Adds everything Ollama's CLI lacks — conversation history, file uploads for document chat, web search, multi-user accounts, voice I/O, and a lot more.
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