GLM 4.5 Flash API Pricing
As of October 10, 2026, GLM 4.5 Flash is free to use on Z.ai. It has a 128,000-token context window and returns up to 32,000 tokens per response.
- Price
- Free
- Context window
- 128,000 tokens
- Max output
- 32,000 tokens
- Providers
- 1
- Added to LiteLLM
- December 2025
GLM 4.5 Flash pricing by provider
1 listing across 1 provider. Token prices are in US dollars per 1M tokens. The highlighted row is the price quoted above.
| Provider | Model name in LiteLLM | Input | Output | Context |
|---|---|---|---|---|
| Z.ai | zai/glm-4.5-flash | $0 | $0 | 128K |
What GLM 4.5 Flash costs in practice
1,000 requests with 2,000 input and 500 output tokens each
| Z.ai | $0 |
100 long-document requests with 100,000 input and 2,000 output tokens each
| Z.ai | $0 |
GLM 4.5 Flash features
- Function calling
Use GLM 4.5 Flash with LiteLLM
Call GLM 4.5 Flash through the LiteLLM Python SDK, or put it behind the LiteLLM proxy and send OpenAI-format requests to /v1/chat/completions. LiteLLM tracks the cost of every request at these prices.
from litellm import completion
response = completion(
model="zai/glm-4.5-flash",
messages=[{"role": "user", "content": "Hello!"}],
)model_list:
- model_name: glm-4.5-flash
litellm_params:
model: zai/glm-4.5-flash
# credentials: see the provider's LiteLLM docs pagecurl http://0.0.0.0:4000/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer sk-1234" \
-d '{
"model": "glm-4.5-flash",
"messages": [{"role": "user", "content": "Hello!"}]
}'GLM 4.5 Flash FAQ
How much does GLM 4.5 Flash cost?
GLM 4.5 Flash is free to use on Z.ai.
What is the context window of GLM 4.5 Flash?
GLM 4.5 Flash has a 128,000-token context window and returns up to 32,000 tokens per response.
Which providers offer GLM 4.5 Flash?
GLM 4.5 Flash is available from Z.ai through LiteLLM, using the model name zai/glm-4.5-flash.
How do I call GLM 4.5 Flash with an OpenAI-compatible API?
Use the LiteLLM Python SDK with model="zai/glm-4.5-flash", or add the model to the LiteLLM proxy's config.yaml and send requests to /v1/chat/completions from any OpenAI client. LiteLLM tracks the cost of every request at the prices on this page.
What features does GLM 4.5 Flash support?
GLM 4.5 Flash supports function calling.
When did LiteLLM add GLM 4.5 Flash?
GLM 4.5 Flash was added to LiteLLM's model price file in December 2025.
Sources
Prices come from LiteLLM's open-source model_prices_and_context_window.json, which LiteLLM uses to calculate the cost of every request. Provider pricing pages:
LiteLLM docs: Z.ai.
Provider pages: Z.ai.
