ZDNET's key takeawaysAnthropic's latest model, Claude Sonnet 4.5, is here. Anthropic's coding tools have become well-regarded amongst developers, with its Claude 4 Sonnet model, released in May, serving as a free and reliable coding assistant for many. What's new in Claude 4.5 Sonnet? Now, Claude Sonnet 4.5 has lapped that last model, outperforming it on the SWE-bench Verified evaluation, a human-filtered subset of the SWE-bench. Claude Sonnet 4.5 also outperformed leading models from competitors, including GPT-5 Codex, GPT-5, and Gemini 2.5 Pro.