OpenAI

OpenAI: gpt-oss-120b

openai/gpt-oss-120b

gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimized to run on a single H100 GPU with native MXFP4 quantization. The model supports configurable reasoning depth, full chain-of-thought access, and native tool use, including function calling, browsing, and structured output generation.

  • Context window: 131,072 tokens
  • Input: text
  • Output: text
  • Pricing: $0.039/M input tokens, $0.18/M output tokens

View on OpenRouter. Model data sourced from OpenRouter.