Z.ai: GLM-4.5-Flash
GLM-4.5-Flash is a reasoning model from Z.ai released on Jul 28, 2025. It reads text and writes text, with a 131K token context window and up to 98K tokens per reply.
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It costs $0 per million input tokens and $0 per million output tokens.
It supports tool calling, structured JSON output and prompt caching, and its weights are open, so you can host it yourself.
5 providers serve it, including EmpirioLabs AI, Tempr Gateway and UnoRouter.
- Modalities
- In / out price
- $0 / $0 per 1M
- Context
- 131K
- Max output
- 98K
- Released
- Jul 28, 2025
- Knowledge cutoff
- Apr 2025
- Tool calling
- Structured output
- Reasoning
- Prompt caching
- Open weights
- Free to use
GLM-4.5-Flash pricing
USD, as listed on Oct 15, 2026. Most bills are input heavy, so the cached input rate matters as much as the headline price.
| Input | $0 / 1M tokens | |
|---|---|---|
| Output | $0 / 1M tokens | |
| Cached input (read) | $0 / 1M tokens | |
| Cache write | $0 / 1M tokens |
GLM-4.5-Flash providers
5 providers serve it, including EmpirioLabs AI, Tempr Gateway and UnoRouter. Each host sets its own price and limits, so the cheapest one is not always the one with the longest context.
| Provider | Input /M | Output /M | Cache read /M | Context | Max output |
|---|---|---|---|---|---|
| Zhipu AI First party | $0 | $0 | $0 | 131K | 98K |
| EmpirioLabs AI | $0 | $0 | – | 200K | 98K |
| Tempr Gateway | $0 | $0 | $0 | 131K | 98K |
| UnoRouter | $0 | $0 | – | 131K | 98K |
| Z.AI | $0 | $0 | $0 | 131K | 98K |
What GLM-4.5-Flash costs per month
Pick a workload close to yours or type your own volumes.
Supported request parameters
What you can set when you call GLM-4.5-Flash through an OpenAI compatible API.
- Tools
tools - Structured outputs
structured_outputs - Reasoning
reasoning - Temperature
temperature
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GLM-4.5-Flash questions
How much does the GLM-4.5-Flash API cost?
$0 per million input tokens and $0 per million output tokens, with cached input at $0. The estimator on this page turns that into a monthly bill for your own workload.
What is the context window of GLM-4.5-Flash?
131,072 tokens of input, and it can write up to 98,304 tokens in one reply. As a rough guide, a million tokens is around 750,000 English words.
Which providers serve GLM-4.5-Flash?
5 providers serve it, including EmpirioLabs AI, Tempr Gateway and UnoRouter. Prices differ by host, so the Providers table on this page lists each one with its input and output price.
Does GLM-4.5-Flash support tool calling?
Yes. It accepts tool definitions and can return JSON that matches a schema, which is what an agent needs to call your APIs.
Is GLM-4.5-Flash open source?
Its weights are published, so you can run it on your own hardware or a cloud of your choice. Read the license before commercial use.
When was GLM-4.5-Flash released?
Jul 28, 2025, with training data up to Apr 2025.
Catalog data from models.dev (MIT licensed), refreshed daily, last on Oct 15, 2026. The summary is written from these facts.
Building on GLM-4.5-Flash?
I test your real tasks on it and the two closest alternatives, then ship the agent on whichever wins on cost and accuracy.
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