GLM 5.3

GLM-5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It supports text input and output with a 1M-token context window, and improves on GLM-5.2 in coding and in the balance between performance and token efficiency. Reasoning is always on and cannot be disabled. Reasoning efforts `low`, `high`, and `max` are supported; `max` is the default.

ChatZhipu1M tokens$1.5261 / $4.7963 · 1M

z-ai/glm-5.3

Context
1M tokens
Completion cap
131,072
Tools
Yes
JSON
Yes
Released
2026-08-18

Call it from Geek Hub

Same OpenAI SDK. Change the base URL and the model id.

curl https://api.geekhub.mx/v1/chat/completions \
  -H "Authorization: Bearer $GEEKHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "z-ai/glm-5.3",
    "messages": [{"role": "user", "content": "Hola"}]
  }'
Get an API key

Frequently asked questions

What is GLM 5.3?
GLM-5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It supports text input and output with a 1M-token context window, and improves on GLM-5.2 in coding and in the balance between performance and token efficiency. Reasoning is always on and cannot be disabled. Reasoning efforts `low`, `high`, and `max` are supported; `max` is the default. GLM 5.3 runs on the Geek Hub API (OpenAI-compatible). Model id: z-ai/glm-5.3.
Is GLM 5.3 free?
No. Input is $1.5261 per 1M tokens and output is $4.7963 per 1M tokens on Geek Hub (markup included).
What is the context length of GLM 5.3?
GLM 5.3 has a 1M tokens context window. It supports up to 131,072 completion tokens.
Does GLM 5.3 support tool calling and structured outputs?
GLM 5.3 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
When was GLM 5.3 released?
GLM 5.3 was released on 2026-08-18.

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