Overview
GLM-5.1 is a 753.9B-parameter Mixture-of-Experts model from zai-org (Z.AI).
- License: Mit
- Context length: 198K tokens
- Languages: en, zh
- Minimum hardware: ~422 GB VRAM
- Strengths: reasoning and on-device inference
Highlights
- Agentic engineering — GLM-5.1 is a flagship model built for repo-level software work.
- Tool calling — native function invocation to drive multi-step agent loops.
- Long-context reasoning — a 198K-token window holds large codebases and documents.
- Open MIT weights — a 753.9B MoE released under a permissive license.
What it is good at
GLM-5.1's strengths line up with its stated capabilities — tools, thinking, reasoning, and code. The model holds up across long, multi-step tasks rather than single-shot answers.
- Agentic coding — built for repo-level work: editing across files, running experiments, and finding blockers, which is what drives its SWE-Bench Pro and Terminal-Bench results.
- Tool calling — native support for invoking functions and external tools, so it can drive an agent loop that reads files, runs commands, and acts on the output.
- Long-context reasoning — the 198K window lets it keep a large codebase, spec, or document set in working memory while it thinks through a problem step by step.
Running it locally
This is a heavy model. At 753.9B total parameters, the FP8 checkpoint needs around 860GB of memory to serve, and full precision pushes past 1.5TB — multi-GPU or cluster territory. Quantized GGUF builds bring it down sharply: 4-bit lands near 476GB, and aggressive 2-bit dynamic quants fit in roughly 240GB, which a 256GB Mac Studio or a multi-card workstation can hold. Expect a few tokens per second on consumer hardware. The context window runs to 198K tokens.
huggingface-cli download zai-org/GLM-5.1
From there you can serve it with vLLM or SGLang (both have GLM-5.1 recipes), load a quantized GGUF through llama.cpp, or open it in Atomic Chat with one click and run it fully on-device.
License
GLM-5.1 is released under the MIT license, one of the most permissive options available. You can download, modify, fine-tune, and deploy it commercially with no royalty fees or usage restrictions, which is what makes self-hosting it in Atomic Chat possible.