# GLM-4.5-Air

> Z.ai's lightweight 106B/12B MoE agentic model — near-flagship reasoning and tool use, MIT-licensed, runs on a single 24GB+ GPU.

- Maker: Z.ai (Zhipu / GLM)
- Line: GLM Air
- Canonical page: https://ai-tldr.dev/models/glm-4-5-air/
- Updated: 2026-06-18

## In short

GLM-4.5-Air is the compact member of Z.ai's (Zhipu) GLM-4.5 family, released on 28 July 2025 alongside the larger GLM-4.5 flagship. It has a 128K-token context window and costs $0.20 per million input tokens and $1.10 per million output tokens. You can use it through Z.ai API Platform and OpenRouter.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 128K (max output 96K) | [1] |
| Input price | $0.20 / 1M tokens | [2] |
| Output price | $1.10 / 1M tokens | [2] |
| Licence | MIT · open weights | [1] |
| Released | 28 July 2025 | [3] |
| Parameters | 106B total · 12B active | [1] |
| Knowledge cutoff | Not disclosed | [1] |

## Sources

1. [GLM-4.5-Air model card (Hugging Face)](https://huggingface.co/zai-org/GLM-4.5-Air)
2. [Z.ai pricing](https://docs.z.ai/guides/overview/pricing)
3. [GLM-4.5 series announcement (Z.ai blog)](https://z.ai/blog/glm-4.5)

## Overview

GLM-4.5-Air is the compact member of Z.ai's (Zhipu) GLM-4.5 family, released on 28 July 2025 alongside the larger GLM-4.5 flagship. It is a Mixture-of-Experts model with 106 billion total parameters and 12 billion active per token, designed to deliver near-flagship reasoning, coding, and agentic ability at a fraction of the size and cost. The full GLM-4.5 sibling uses 355B total / 32B active; GLM-4.5-Air trades raw capacity for efficiency, fitting on a single high-memory GPU.

Like GLM-4.5, GLM-4.5-Air is a hybrid reasoning model: it exposes a 'thinking' mode for complex reasoning and tool use and a 'non-thinking' mode for fast, direct answers. It targets agent-centric applications — long-horizon coding, function calling, and tool orchestration — rather than just chat. The weights are published under the MIT license on Hugging Face and ModelScope, so the model can be downloaded, fine-tuned, and used commercially.

On Z.ai's own 12-benchmark aggregate covering agentic, reasoning, and coding (ARC) tasks, GLM-4.5-Air scores 59.8, close behind the 63.2 of the full GLM-4.5 while running far cheaper. It is the cost-efficient default in the GLM Air line and the direct predecessor to later Air/Flash-tier releases such as GLM-4.6 and GLM-4.7-Flash.

## Benchmarks

- MMLU-Pro: 81.4% ([source](https://huggingface.co/zai-org/GLM-4.5-Air))
- AIME 2024: 89.4% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- MATH-500: 98.1% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- GPQA Diamond: 71.72% ([source](https://huggingface.co/zai-org/GLM-4.5-Air))
- BFCL-v3 (function calling): 76.4% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- LiveCodeBench: 70.7% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- SWE-bench Verified: 57.6% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- TAU-bench (Airline): 60.8% ([source](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air))
- ARC aggregate (12 benchmarks): 59.8 ([source](https://huggingface.co/zai-org/GLM-4.5-Air))

## Pricing

- Input: $0.20 / 1M tokens
- Output: $1.10 / 1M tokens

Official Z.ai API list price for GLM-4.5-Air. Third-party hosts (e.g. OpenRouter at ~$0.13 / $0.85) and open weights are also available.

Source: https://docs.z.ai/guides/overview/pricing

## Strengths

- Strong agentic and tool-use ability for its size — built specifically for function calling and multi-step agent workflows
- Open MIT-licensed weights: free to download, fine-tune, and use commercially via Hugging Face and ModelScope
- Hybrid thinking / non-thinking modes let you trade reasoning depth for latency in a single checkpoint
- Excellent math and reasoning for a 12B-active model (AIME 2024 89.4, MATH-500 98.1)
- Much cheaper than the GLM-4.5 flagship ($0.20 / $1.10 vs $0.60 / $2.20 per 1M tokens) with close aggregate scores
- Compact 106B MoE design runs on a single high-memory GPU, lowering self-hosting cost

## Best for

- Agentic coding assistants and autonomous coding agents that call tools over long horizons
- Self-hosted deployments where open weights and commercial-friendly licensing matter
- Function-calling and tool-orchestration backends needing reliable structured output
- Cost-sensitive reasoning workloads (math, logic, analysis) that can't justify a flagship-size model
- Fine-tuning and secondary development on a permissively-licensed base
- Latency-flexible apps that switch between fast non-thinking replies and deeper thinking-mode reasoning

## How to access

- [Z.ai API Platform](https://docs.z.ai/guides/llm/glm-4.5) — model id `glm-4.5-air`
- [OpenRouter](https://openrouter.ai/z-ai/glm-4.5-air) — model id `z-ai/glm-4.5-air`

## GLM Air versions

- GLM-4.5-Air (28 July 2025) — this page

## FAQ

### How big is GLM-4.5-Air?

GLM-4.5-Air is a Mixture-of-Experts model with 106 billion total parameters and 12 billion active per token. That makes it the compact sibling of the full GLM-4.5, which has 355B total / 32B active parameters.

### Is GLM-4.5-Air open source?

Yes. Z.ai released the GLM-4.5-Air weights under the MIT license on Hugging Face and ModelScope. They can be downloaded, fine-tuned, and used commercially, including for secondary development.

### What is GLM-4.5-Air's context window?

Z.ai's developer documentation lists a 128K-token context window and up to 96K tokens of output for GLM-4.5-Air. Some third-party hosts advertise the underlying 131,072-token (128K) limit.

### How much does GLM-4.5-Air cost?

On the official Z.ai API, GLM-4.5-Air is priced at $0.20 per million input tokens and $1.10 per million output tokens — about a third of the GLM-4.5 flagship's $0.60 / $2.20. Open weights and cheaper third-party hosts (e.g. OpenRouter around $0.13 / $0.85) are also available.

## Links

- [Z.ai — official site](https://z.ai)
- [GLM-4.5-Air model card (Hugging Face)](https://huggingface.co/zai-org/GLM-4.5-Air)
- [GLM-4.5 series — Z.ai developer docs](https://docs.z.ai/guides/llm/glm-4.5)
- [GLM-4.5: Agentic, Reasoning, and Coding (ARC) Foundation Models — arXiv 2508.06471](https://arxiv.org/abs/2508.06471)
- [GLM-4.5 series announcement (Z.ai blog)](https://z.ai/blog/glm-4.5)
- [GLM-4.5 GitHub repository](https://github.com/zai-org/GLM-4.5)
- [GLM-4.5-Air benchmark & price analysis (Artificial Analysis)](https://artificialanalysis.ai/models/glm-4-5-air)
- [GLM-4.5 vs GLM-4.5-Air benchmark comparison (LLM-Stats)](https://llm-stats.com/models/compare/glm-4.5-vs-glm-4.5-air)
- [Z.ai pricing](https://docs.z.ai/guides/overview/pricing)
- [Z.ai Chat playground](https://chat.z.ai)

Source: AI/TLDR LLM registry, https://ai-tldr.dev/models/glm-4-5-air/