Anthropic just released Claude Sonnet 5.5 . It is the second model in the Claude 5.5 family, following Claude Opus 5.5 . Anthropic positions it as a faster, lower-cost complement to Opus 5.5. It targets well-scoped everyday tasks, bug fixing, and polished documents, slides, and spreadsheets. Is it deployable? Yes, It is live on the Claude Platform as claude-sonnet-5-5 , plus AWS, Google Cloud, and Microsoft Azure. It is a closed-weights model, so self-hosting is not an option. What Changed Versus Sonnet 5 Anthropic reports 4 main upgrades over Sonnet 5 : Speed: output generation is 30%+ faster, making it the fastest Sonnet to date. Cost per task: up to 30% lower, because it needs fewer tokens and tool calls. Writing: clearer prose, with early testers calling it a better collaboration partner. Vision and long-horizon work: it is the first Sonnet to beat Pokémon Red using only screenshots. Specs from the models overview : 1M-token context, 128K max output, and a June 2026 reliable knowledge cutoff. Adaptive thinking is on by default. Effort runs across 5 levels: low, medium, high, xhigh, and max. Benchmarks All scores below are vendor-reported in the launch post . Methodology lives in the Sonnet 5.5 System Card . Terminal-Bench 4.0: 70.6%, versus 10.3% for Sonnet 5 and 66.4% for Opus 5.5 at Xhigh. CursorBench 4.0: 55.5%, about 2 points below Opus 5.5 (57.8%). FrontierCode 1.1: 52.1% at Xhigh and 46.2% at Max. GPT-6 Sol scored 49.3%. GDPval-AA v2.1: 1844, versus 1846 for Opus 5.5 and 1449 for Sonnet 5. OSWorld 2.1: 80.1% on computer use, close to Opus 5.5 (81.8%). Humanity’s L
Source: MarkTechPost