# 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.

- Page: https://models.litellm.ai/models/glm-4.5-flash
- Lab: Z.ai
- LiteLLM model name: `zai/glm-4.5-flash`
- Context window: 128,000 tokens
- Max output: 32,000 tokens
- Added to LiteLLM: December 2025
- Prices updated: October 10, 2026

## Pricing by provider

Token prices in USD per 1M tokens.

| Provider | Model name | Input | Output | Cache read | Per image | Per second | Context |
|---|---|---|---|---|---|---|---|
| Z.ai | `zai/glm-4.5-flash` | $0 | $0 | – | – | – | 128K |

## Cost examples

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

## Features

Supported: Function calling.

## Use it with LiteLLM

```python
from litellm import completion

response = completion(
    model="zai/glm-4.5-flash",
    messages=[{"role": "user", "content": "Hello!"}],
)
```

## 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.

Source: LiteLLM model price file, https://github.com/BerriAI/litellm/blob/main/model_prices_and_context_window.json