GLM-5.1 vs GLM-5.1

GLM-5.1 is Z.ai's (formerly Zhipu AI) open-weight model released April 7, 2026 under the MIT license. It's a 744-billion-parameter Mixture-of-Experts architecture with 40 billion active parameters per token, a 200K-token context window, and a 131K maximum output length — and it became the first open-source model ever to lead SWE-bench Pro, scoring 58.4% versus Claude Opus 4.6's 57.3%. The training story is almost as remarkable as the performance. GLM-5.1 was trained entirely on approximately 100,000 Huawei Ascend 910B chips using the MindSpore framework — no Nvidia hardware was used at any point. That makes it one of the first frontier-tier models to demonstrate that the CUDA monoculture isn't technically mandatory for training state-of-the-art models. Z.ai became the first publicly traded foundation model company via a Hong Kong IPO in January 2026 (~$558M raised). The model is free to download from HuggingFace and also available via API at $0.95 per million input tokens. In agentic demonstrations, it has run autonomously for eight hours straight — 655 planning and execution iterations — without human checkpoints.

GLM-5.1 is Z.ai's (formerly Zhipu AI) latest open-weight model — a 744-billion-parameter Mixture-of-Experts architecture with 40B active parameters that claims the #1 spot on SWE-bench Pro with a score of 58.4, beating GPT-5.4 (57.7) and Claude Opus 4.6 (57.3). It ships under the MIT license with a 200K-token context window and maximum output of 131,072 tokens. What makes GLM-5.1 geopolitically notable is its training infrastructure: every GPU in the stack is a Huawei Ascend 910B — zero Nvidia hardware involved. This is one of the first frontier-competitive models to prove that non-Western AI compute can reach the top of benchmark leaderboards. It's a post-training upgrade to GLM-5, meaning architectural choices were locked in; the performance lift came from smarter RLHF and agentic training data. For developers, the value prop is straightforward: MIT license, frontier-level coding performance, and a 200K context window. The model is optimized for multi-step agentic tasks — it breaks down complex problems, runs experiments, reads results, and iterates. Real-world quality is still being validated beyond SWE-bench, but for teams that need a commercially-deployable open-weight coding model, this is the current benchmark king.