Model page
GLM 5.1
Z.ai's GLM-5.1 via Fireworks: next-generation flagship for agentic engineering, stronger coding, and sustained long-horizon task performance. 202k context. Uses 2 premium requests per send before length multipliers. Does not support web search, image input, or function calling.
Key dates
We use concrete dates and keep them consistent across the site.
Capability
Context window
202,800 tokens
Modalities
Input and output
Input: Text
Output: Text
Features
Availability notes
Cached input: $0.26 / 1M tokens · 2 premium requests per send before length multipliers · Function calling not supported on Fireworks serverless · Fine-tuning not supported on Fireworks serverless
ChatGPT
GPT‑4o retirement (ChatGPT)
OpenAI is retiring GPT‑4o inside ChatGPT on February 13, 2026. This does not automatically imply API removal.