1 Best Open Source ChatGPT Alternatives

ChatGPT is OpenAI's hosted chat interface for its language models, used for answering questions, drafting text, writing code, and general conversation. It runs entirely on OpenAI's servers, with paid tiers offering higher usage limits, newer models, and features like file uploads and custom instructions.

People look for open-source alternatives to ChatGPT mainly to run a chat interface against models they choose and control, rather than being tied to OpenAI's models, pricing, and data handling. Some want to connect a chat interface to locally-run models for privacy, since nothing leaves their own machine. Others want to mix providers, using different models for different tasks through a single interface, or need self-hosting for internal company use where sending data to an external API is not acceptable.

Open WebUI is a common choice here. It is a self-hosted web interface, similar in feel to ChatGPT, that connects to local model runners like Ollama as well as OpenAI-compatible APIs, so it can serve as a front end for open models or as an alternate client for the OpenAI API itself. It supports multiple users, chat history, and document upload for retrieval-augmented conversations.

Note that Open WebUI is an interface, not a model, so the quality of responses depends entirely on what model you connect it to, whether that is a locally-hosted open model or a hosted API. Before adopting it, check whether the models you plan to run locally meet your quality needs for your use case, since open models vary widely in capability. Also confirm your hardware can run the model size you want, since local inference requires meaningful GPU or CPU resources.