Model page
GPT OSS 120b
OpenAI's open-weight 117B MoE via Fireworks. Production-grade reasoning, agentic tasks, function calling. 131k context. Does not support web search or image input.
Key dates
We use concrete dates and keep them consistent across the site.
Capability
Context window
131,072 tokens
Capability
Max output
20,000 tokens
ChatGPT
GPT‑4o retirement (ChatGPT)
OpenAI is retiring GPT‑4o inside ChatGPT on February 13, 2026. This does not automatically imply API removal.