Anthropic launches new vibe coding model Claude Sonnet 4.5: All you need to know

Anthropic launched its latest artificial intelligence (AI) coding model, Claude Sonnet 4.5, on Monday, claiming it could handle longer coding sessions, and perform better on reasoning and mathematical tasks. The AI major also claimed that the model has shown significant improvement in computer use.

The new model has been rolled out as Anthropic eyes global expansion — including plans for India — to meet the rising enterprise demand for AI.

Alphabet and Amazon-backed Anthropic has been marketing Claude’s coding and data-analysis skills to regulated industries and teams that want models to work across multiple software tools.


Claude Sonnet 4.5 features

Anthropic claims that Claude Sonnet 4.5 scores the highest against its own models as well as OpenAI’s GPT-5 and GPT-5 Codex and Google’s Gemini 2.5 Pro on the SWE-bench verified evaluation. This benchmark measures real-world software coding abilities.

Claude Sonnet 4.5 was seen maintaining focus for more than 30 hours on complex, multi-step tasks, Anthropic said.

Claude Sonnet 4.5 also shows improvements in computer use. It leads at 61.4% on OSWorld, a benchmark that tests AI models on real-world computer tasks.

According to Anthropic, experts in finance, law, medicine, and STEM found Sonnet 4.5 shows dramatically better domain-specific knowledge and reasoning compared to older models, including Opus 4.1.

Claude Sonnet 4.5 availability and price

Anthropic said Claude Sonnet 4.5 is available everywhere today. Developers can access the coding model via Claude API.

Pricing remains the same as Claude Sonnet 4, at $3/$15 per million input/output tokens, the AI company said.