GLM 5.1 is Z.ai's (formerly Zhipu AI) flagship open-source AI model. It uses a mixture-of-experts architecture with 754B total parameters and is designed for long-horizon agentic engineering tasks.

How does GLM 5.1 compare to Claude Opus 4.6?

On SWE-Bench Pro, Z.ai claims GLM 5.1 outperforms Claude Opus 4.6. On the Arena Code leaderboard, it ranks third, behind Claude Opus 4.6 variants. On reasoning and math benchmarks (GPQA Diamond, AIME 2026), Claude Opus 4.6 holds an advantage. GLM 5.1 is priced 80 to 87% lower.

Is GLM 5.1 open source?

Yes. GLM 5.1 is released under an MIT license with weights available on Hugging Face.

What is GLM 5.1 pricing?

Input tokens are priced at $1.05 to $1.40 per million tokens. Output tokens range from $3.50 to $4.40 per million tokens, depending on provider. It is available through Z.ai's API and OpenRouter.

Can I run GLM 5.1 locally?

Yes. GLM 5.1 supports self-hosting via vLLM, SGLang, xLLM, and KTransformers. Unsloth provides GGUF quantizations starting at approximately 220GB, which is within range for high-end consumer and workstation hardware.