Anthropic’s Claude Sonnet 4.5 AI Model Introduced as the ‘Best Coding Model in the World’

Anthropic released the Claude Sonnet 4.5 artificial intelligence (AI) model on Monday. Calling it the “best coding model in the world,” the company highlighted that it has been improved across multiple domains including, coding, agentic operations, computer use, reasoning, and domain-specific knowledge. The new model will be available across Claude website and mobile apps, Claude Code, the application programming interface (API), as well as the under-testing Claude for Chrome extension. Anthropic also claims that the AI model can work autonomously for 30 hours on a task.

Claude Sonnet 4.5 Features and Capabilities

In a blog post, the AI firm detailed the new AI model. Based on the company's claims, Claude Sonnet 4.5 is designed to make a massive leap in coding and agentic performance, although other areas have also been upgraded. However, despite the upgrades, the new model only offers incremental improvements and does not bring any new capability or modality.

Based on internal testing, Anthropic claims that the large language model (LLM) achieved a score of 77.2 percent on the SWE bench-Verified benchmark, which measures the agentic coding capabilities of a model. Notably, this is higher than what OpenAI's GPT-5 and Google's Gemini 2.5 Pro scored, or the company's Opus 4.1.

Claude Sonnet 4.5 demo

Gadgets 360 staff members briefly tested the model's coding capabilities. We asked it to create a WhatsApp-like messaging chatbot, complete with individual and group chats, as well as audio and video calls. In just two minutes, it wrote 436 lines of code in React, and was able to generate a preview for the fully-functional (minus the server connectivity) interface.

Other benchmarks where the AI model is said to have led the charts include Terminal Bench, OSWorld for Computer Use, AIME 2025 for high-school mathematics, and Finance Agent for financial analysis. In reasoning-based GPQA Diamond, Gemini 2.5 Pro fared better, while GPT-5 led the charts in MMMU benchmark for visual reasoning and MMLU for multilingual performance.

Anthropic also claimed that the model surpassed all the company's older models in domain-specific knowledge and reasoning across finance, law, medicine, and STEM fields.

Coming to safety, the AI firm claims that the Claude Sonnet 4.5 is its “most aligned frontier model.” Anthropic claims that it has reduced behaviours such as sycophancy, depeception, power-seeking, and the tendency to encourage delusional thinking. Safeguards have been taken to protect it from prompt injections as well.