Open-source chat interfaces
Apps and self-hosted platforms that give you a ChatGPT-style chat window over models you choose: desktop clients for one person, and servers with sign-in, roles and document search for a team. Most connect to local models through Ollama as well as to hosted providers with your own keys.
A self-hosted chat platform for Ollama and OpenAI-compatible models with document search over 9 vector databases, web search, image generation, roles and single sign-on, under a BSD-3 licence with an added branding clause.
LobeHub, formerly LobeChat, is an agent workspace with an agent builder, agent groups, scheduled runs, editable memory and a library of over 10,000 tools and MCP plugins, under a community licence that needs a paid licence to distribute a modified version.
An MIT all-in-one AI app from Mintplex Labs for chatting with your documents with citations, running agents with MCP, and using any of 39 model providers including local llama.cpp and Ollama, as a desktop app or a multi-user Docker server.
An AGPL-3.0 desktop client for Windows, macOS and Linux that connects OpenAI, Gemini, Anthropic and local Ollama or LM Studio models, with 300+ preset assistants, side-by-side model chats, file support and MCP servers.
An AGPL-3.0 desktop app for local models, formerly text-generation-webui, with five engines including llama.cpp and ExLlamaV3, an OpenAI and Anthropic-compatible API, tool calling, file chat, image generation and LoRA training, fully offline.
An MIT self-hosted chat platform that puts Anthropic, OpenAI, Google, Bedrock, Azure, Ollama and any OpenAI-compatible model in one interface, with agents, MCP, a code sandbox, web search, artifacts and multi-user sign-in.
An Apache-2.0 desktop app from Menlo Research that downloads and runs open models from Hugging Face on your own computer, connects to OpenAI, Anthropic and others when you want, serves a local OpenAI-compatible API, and supports MCP.
The GPL-3.0 community edition of a desktop and mobile chat client for ChatGPT, Claude, Gemini and local Ollama models that keeps conversations on your device, with a separate pro edition synced from the same code.
Hugging Face's Apache-2.0 chat interface, the code behind HuggingChat, that talks to any OpenAI-compatible API, stores chats in MongoDB, calls MCP tools, and can route each message to a model automatically.
Questions people ask
What is the best open-source ChatGPT alternative?
For a team on a server: Open WebUI, the most complete, under a BSD-3 licence with a branding clause, or LibreChat (MIT) with Anthropic, OpenAI, Google and Ollama built in. For one person on a desktop: Jan (Apache-2.0) for local models, AnythingLLM (MIT) for chatting with documents, or Chatbox (GPL-3.0) across desktop and phone.
Which open-source chat apps run fully offline?
Jan, TextGen, AnythingLLM, Open WebUI, Cherry Studio and Chatbox all run local models, through their own llama.cpp engine or through Ollama and LM Studio. TextGen's README states zero telemetry and no remote update requests; AnythingLLM's telemetry is on by default until you turn it off.
Which open-source chat interfaces support multiple users?
Open WebUI (roles, groups, LDAP, OAuth single sign-on and SCIM), LibreChat (OAuth2, LDAP and email sign-in with an admin panel), AnythingLLM in its Docker version, and TextGen's multi-user mode for small trusted teams. The desktop apps are for one person.
Are these chat interfaces really open source?
Most are, under MIT, Apache-2.0, GPL-3.0 or AGPL-3.0. Two are source available: Open WebUI's licence forbids removing its branding above 50 users without permission or a paid licence, and LobeHub's needs a paid licence to distribute a modified version. Each project page states its licence and why.
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