GLM 5.1 vs GLM 4.7 FlashX

GLM 5.1 vs GLM 4.7 FlashX at a glance

GLM 5.1 and GLM 4.7 FlashX are both Z.ai models in the Text Generation category, available through the EmpirioLabs API.

Key differences

• GLM 5.1 is the newer release (Apr 7, 2026); GLM 4.7 FlashX was released on Jan 19, 2026.
• GLM 4.7 FlashX has the larger context window: 202.8K tokens, against 202.7K for GLM 5.1.
• GLM 4.7 FlashX returns up to 131,072 output tokens per response, GLM 5.1 up to 128,000.
• Capabilities listed only for GLM 4.7 FlashX: web search.

GLM 5.1 vs GLM 4.7 FlashX: specs

GLM 5.1 vs GLM 4.7 FlashX: API pricing

Live rates from the EmpirioLabs catalog for both models. Each rate card always matches what the API charges.

GLM 5.1 vs GLM 4.7 FlashX: API parameters

Request parameters each model lists on EmpirioLabs, with the allowed values or range where one applies. A dash marks a parameter the model does not list.

GLM 5.1 vs GLM 4.7 FlashX: limits and notes

GLM 4.7 FlashX

Built-in web search is optional through tool_web_search and adds $0.033 per request when enabled.

How to call GLM 5.1 and GLM 4.7 FlashX

GLM 5.1 serves the OpenAI-compatible Chat Completions API. Point any OpenAI SDK at https://api.empiriolabs.ai/v1 with your EmpirioLabs API key and use the model id glm-5-1. Both models are called through the same endpoint. Set model to glm-5-1 or glm-4-7-flashx. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/chat/completions \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "glm-5-1",
    "messages": [
      {"role": "user", "content": "Write a haiku about the ocean."}
    ]
  }'

GLM 5.1 vs GLM 4.7 FlashX: common questions

What is the difference between GLM 5.1 and GLM 4.7 FlashX?

GLM 5.1 is the newer release (Apr 7, 2026); GLM 4.7 FlashX was released on Jan 19, 2026. GLM 4.7 FlashX has the larger context window: 202.8K tokens, against 202.7K for GLM 5.1. GLM 4.7 FlashX returns up to 131,072 output tokens per response, GLM 5.1 up to 128,000. The specs, rate cards, and parameters on this page come from the live EmpirioLabs catalog.

Which is newer, GLM 5.1 or GLM 4.7 FlashX?

GLM 5.1 is the newer release (Apr 7, 2026); GLM 4.7 FlashX was released on Jan 19, 2026.

Which has the lower rate, GLM 5.1 or GLM 4.7 FlashX?

The two models are priced on different units or tiers, so compare the live rate cards on this page. They always match what the API charges.

Can I switch between GLM 5.1 and GLM 4.7 FlashX without rebuilding my integration?

Yes. Both models use POST /v1/chat/completions with the same EmpirioLabs API key, so most integrations switch by changing the model value. Check the parameters table on this page first if you rely on a model-specific parameter.

Can I try GLM 5.1 and GLM 4.7 FlashX in the browser before integrating?

Yes. Open each model in the EmpirioLabs playground and run the same prompt on both, with the parameters the API exposes.