Z.ai: GLM 4.5 Air (free) — Free AI Model & API

Verified
openrouter/z-ai-glm-4.5-air
chat
Get API key →
Context Window 131K
Max Output 96K
Rate Limit See provider page
Cost $0.00 FREE
Free Period Since Jul 25, 2025
Credit Card Not required
Status Online

Overview

GLM-4.5 Air is the lightweight Mixture-of-Experts variant of Zhipu AI's (Z.ai) flagship GLM model family, available free on OpenRouter. Purpose-built for agent-centric applications with 131K context window. Supports hybrid inference modes — a thinking mode for reasoning and tool use, plus a non-thinking mode for real-time interaction, toggled via a reasoning.enabled parameter. Compact MoE architecture for efficient deployment. Text-only. Also available directly from Z AI's platform. OpenAI-compatible via OpenRouter. Free tier: 200 RPD.

Model ID
z-ai/glm-4.5-air:free
Base URL
https://openrouter.ai/api/v1
Specifications
Context: 131K · Output: 96K · Modality: text · OpenAI Compat: Yes ·Released: Jul 25, 2025

Quick Start

Integrate Z.ai: GLM 4.5 Air (free) with 3 lines of code. See the config generator for Claude Code, Cursor, and more.

from openai import OpenAI

client = OpenAI(
 base_url="https://openrouter.ai/api/v1",
 api_key="YOUR_API_KEY"
)

response = client.chat.completions.create(
 model="z-ai/glm-4.5-air:free",
 messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)
import OpenAI from "openai";

const openai = new OpenAI({
 baseURL: "https://openrouter.ai/api/v1",
 apiKey: "YOUR_API_KEY",
});

const completion = await openai.chat.completions.create({
 model: "z-ai/glm-4.5-air:free",
 messages: [{ role: "user", content: "Hello!" }],
});

console.log(completion.choices[0].message.content);
curl https://openrouter.ai/api/v1/chat/completions \
 -H "Content-Type: application/json" \
 -H "Authorization: Bearer YOUR_API_KEY" \
 -d '{
 "model": "z-ai/glm-4.5-air:free",
 "messages": [{"role": "user", "content": "Hello!"}]
 }'

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Rate Limits & Constraints

Rate Limit See provider page
Context Window 131K
Max Output Tokens 96K
Cost Free — since Jul 25, 2025
Credit Card Not required
OpenAI Compatible Yes — drop-in replacement

OpenRouter Platform Limitations

  • 200 RPD on free tier (1,000 with $10 lifetime credit)
  • Free models may change without notice
  • Some free models have shorter context windows than paid variants

Features & Use Cases

Best For

Chat

Modality Support

text

OpenRouter Highlights

  • 35+ permanently free models
  • OpenAI-compatible endpoint
  • 200 RPD free, 1,000 RPD with $10 lifetime credit
  • One key for 300+ models

Playground — Test Z.ai: GLM 4.5 Air (free)

Test Z.ai: GLM 4.5 Air (free) directly in your browser. Your API key is sent directly to OpenRouter — never stored.

Model: Z.ai: GLM 4.5 Air (free) Get Key

🔒 Your key is never stored — sent directly to the model provider via our server proxy.

Ready to chat with Z.ai: GLM 4.5 Air (free).

Frequently Asked Questions

How do I get an API key for Z.ai: GLM 4.5 Air (free)?

Sign up at OpenRouter to get your API key. No credit card is required — just an email sign-up. Once you have the key, use the code snippets in the Quick Start section above.

Is Z.ai: GLM 4.5 Air (free) really free?

Yes. Z.ai: GLM 4.5 Air (free) is available on OpenRouter's free tier and has been free since Jul 25, 2025. Rate limits apply: See provider page. Always check the provider's terms for any changes to the free tier.

What are Z.ai: GLM 4.5 Air (free)'s rate limits?

See provider page Context window: 131K. Max output: 96K. No credit card required.

What are the best free alternatives to Z.ai: GLM 4.5 Air (free)?

Popular free alternatives include inclusionAI: Ring-2.6-1T, Baidu Qianfan: CoBuddy (free), Owl Alpha. You can also browse all 147+ free models on our site.

More questions? See our full FAQ →

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