GLM-5 vs. Claude Sonnet 5.5

GLM-5 is Z.ai’s most advanced open-source model to date, purpose-built for complex systems engineering, long-horizon planning, and autonomous agent workflows. Building on the foundation of GLM-4.5, it dramatically scales both total parameters and pre-training data while increasing active parameter efficiency. The integration of DeepSeek Sparse Attention allows GLM-5 to maintain strong long-context reasoning capabilities while reducing deployment costs. To improve post-training performance, Z.ai developed slime, an asynchronous reinforcement learning infrastructure that significantly boosts training throughput and iteration speed. As a result, GLM-5 achieves top-tier performance among open-source models across reasoning, coding, and general agent benchmarks. It demonstrates exceptional strength in long-term operational simulations, including leading results on Vending Bench 2, where it manages a year-long simulated business with strong financial outcomes. In coding evaluations such as SWE-bench and Terminal-Bench 2.0, GLM-5 delivers competitive results that narrow the gap with proprietary frontier systems. The model is fully open-sourced under the MIT License and available through Hugging Face, ModelScope, and Z.ai’s developer platforms. Developers can deploy GLM-5 locally using inference frameworks like vLLM and SGLang, including support for non-NVIDIA hardware through optimization and quantization techniques. Through Z.ai, users can access both Chat Mode for fast interactions and Agent Mode for tool-augmented, multi-step task execution. GLM-5 also enables structured document generation, producing ready-to-use .docx, .pdf, and .xlsx files for business and academic workflows. With compatibility across coding agents and cross-application automation frameworks, GLM-5 moves foundation models from conversational assistants toward full-scale work engines.

Claude Sonnet 5.5 is Anthropic’s faster, lower-cost Claude 5.5 model for well-scoped professional work, software development, agentic workflows, and content creation. Anthropic positions it below Claude Opus 5.5 for the most complex open-ended work, but says it can perform comparably on some benchmarks when run at higher effort settings. The model delivers a particularly large improvement in coding, including a 70.6% result on Terminal-Bench 4.0, 46.2% on FrontierCode at Max effort, and 55.5% on CursorBench 4.0. It also scores 1844 on GDPval-AA, 1811 on AA-Briefcase, 64.5% on Humanity’s Last Exam with tools, and 80.1% on OSWorld 2.1 partial. Anthropic reports that Sonnet 5.5 is better at long-horizon work, image understanding, collaboration, and codebase comprehension than Sonnet 5. The company also highlights design-oriented improvements, including the ability to produce polished documents, spreadsheets, slides, and user interfaces with less editing. Sonnet 5.5 generates output more than 30% faster than its predecessor and is Anthropic’s fastest Sonnet model to date. Although its listed token prices are unchanged from Sonnet 5, Anthropic says greater token efficiency can reduce per-task cost by up to 30%. Pricing is $2 per million input tokens, $10 per million output tokens, $2.50 per million cache-write tokens, and $0.20 per million cache-read tokens. The model includes cyber safeguards, biology safeguards, reasoning-extraction protections, and preserved-thinking controls, with some higher-risk cyber requests falling back to Sonnet 5. Claude Sonnet 5.5 is available with zero data retention across Claude products, the Claude Platform, AWS, Google Cloud, and Microsoft Azure under the model name claude-sonnet-5-5.