Grok 4.6 vs. Claude Sonnet 5.5

Grok 4.6 is a frontier AI model from xAI focused on long-running agents, ambitious interactive work, visual projects, coding, research, and knowledge work. The model builds on Grok 4.5 and is designed to stay engaged across complex tasks that unfold over many steps. Users can apply Grok 4.6 to research unfamiliar domains, analyze information, work across codebases, generate applications, create work artifacts, and refine projects through iterative feedback. Its training included a longer supplemental run with curated model-generated data for reasoning and advanced technical concepts, high-quality engineering data, and an improved optimizer and training recipe. xAI also regenerated supervised fine-tuning trajectories across reasoning efforts, agent harnesses, STEM, software engineering, and knowledge work, then filtered problematic traces with model-based checks. Grok 4.6 was trained on agentic reinforcement learning tasks across knowledge work, general coding, kernel optimization, web development, computer-aided design, and related technical environments. The model is positioned as especially useful for turning broad product ideas into working first versions because it can structure an application, implement core interactions, and improve the result over several rounds. It also produces stronger first passes on visual and interactive projects than Grok 4.5, making it useful when teams need a substantial starting point for iteration. xAI reports that Grok 4.6 performs strongly across benchmarks such as Artificial Analysis Intelligence Index, GDPVal-AA, DeepSWE, CursorBench, FrontierCode, APEX-Agents, Terminal-Bench, APEX-SWE, AA-Briefcase, and Harvey LAB. Grok 4.6 is available in Cursor, Grok Build, the xAI API, OpenRouter, Vercel, Cloudflare, and other partner environments, with a fast variant also available at higher pricing.

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.