Z.ai Drops Powerful Agentic Models — GLM-4.5 and 4.5-Air

Chinese AI firm Z.ai (formerly Zhipu AI) has open-sourced two powerful models—GLM4.5 and GLM4.5Air—designed for agent-style reasoning, tool use, planning, and even generating PowerPoint-style slides.

This development makes high-end AI capabilities freely accessible to developers and enterprises.

What Are These Models?

GLM‑4.5 is a massive model with 355 billion total parameters and 32 billion active parameters, optimized for complex tasks and agentic behavior like planning and tool use.

GLM‑4.5‑Air, with 106 billion total parameters (12B active), offers a lightweight, efficient alternative with strong capability in lower-cost or cloud-light deployments.

These models feature a hybrid reasoning architecture—a “thinking mode” for deep reasoning and tool invocation, and a “non‑thinking mode” for fast, immediate responses.

Benchmark Performance

Both models were evaluated on 12 standard benchmarks covering agentic tasks, reasoning, and coding:

• GLM‑4.5 ranked 3rd globally overall, and 1st among open-source and domestic Chinese models.
• GLM‑4.5‑Air achieved a solid 6th place worldwide, offering impressive efficiency for its scale.
• On agentic benchmarks like TAU-bench and BFCL-v3, GLM‑4.5 matched the performance of Anthropic’s Claude 4 Sonnet.
• On BrowseComp (web-browsing tasks), it scored 26.4%, outperforming Claude‑4‑Opus (18.8%) and approaching the performance of o4‑mini‑high.

Background

Z.ai’s announcement follows OpenAI’s August 2025 release of open-weight models gpt-oss-120b and gpt-oss-20b, which offer nearly closed-model performance with full downloadability and fine-tunability.

OpenAI highlighted these models as democratizing tools, aligned with democratic values and global competition.

Availability

Both models are available under open licenses (MIT/Apache‑style), and hosted on platforms like GitHub, Hugging Face, and ModelScope.

Developers can run them directly via Z.ai’s API, which supports OpenAI-compatible function calling for agentic workflows.

News Gist:

China’s Z.ai has released two powerful open-source agentic AI models—GLM-4.5 (355B) and 4.5-Air (106B).

These models support reasoning, planning, slide creation, and rival top global models, offering full transparency and free access to developers and enterprises.