Closed-Source Model
An AI model whose weights and training details are proprietary and not publicly released.
Full Definition
Closed-source models are developed and deployed by companies that do not release their model weights, training data, or full architecture details. Users access them only through APIs or consumer products. Examples include GPT-4 (OpenAI), Claude (Anthropic), and Gemini Ultra (Google). The closed-source approach lets companies protect proprietary investment, enforce usage policies, and patch safety issues without enabling bad actors to bypass safeguards by directly modifying weights. Critics argue it reduces reproducibility, academic scrutiny, and developer flexibility. The closed-versus-open debate is one of the central tensions in the AI industry.
Examples
GPT-4's weights have never been released; developers can only use it through OpenAI's API under their usage policies.
Anthropic does not publish Claude's architecture details, making independent safety audits difficult.
Apply this in your prompts
PromptITIN automatically uses techniques like Closed-Source Model to build better prompts for you.
Related Terms
Open-Source Model
A model whose weights are publicly available, enabling local deployment, inspect…
View →Foundation Model
A large model trained on broad data that can be adapted to many downstream tasks…
View →Fine-Tuned Model
A pretrained model whose weights have been updated on a specific dataset for a t…
View →