We benchmarked Claude Sonnet 4.5 as it narrows the gap with Opus 4.1 in code review, catching more critical bugs with 41% important hits at lower cost.

October 2, 2025 - Claude Sonnet 4.5 is Anthropic’s ... 2025, Sonnet 4.5 is definitely a contender and also excels at complex autonomous “agent” behavior and exhibits substantial gains in reasoning and mathematics....

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. ... We're seeing state-of-the-art coding performance from Claude Sonnet 4.5, with significant improvements on longer horizon ...

September 29, 2025 - Claude Sonnet 4.5 is the best coding model in the world. It’s the strongest model for building complex agents. It’s the best model at using computers.

September 29, 2025 - Anthropic just rolled out Claude Sonnet 4.5, and, of course, we spent the weekend using it to code and running long agentic tasks with it. The headline: It’s noticeably faster, more steerable, and more reliable than · Opus 4.1—especially inside Claude Code. In head-to-head tests it blitzed through a large pull request review in minutes, handled multi-file reasoning without wandering, and stayed terse when we asked it to.

October 23, 2025 - Sonnet 4.5 focused on coding. The model shined in · Claude Code, wowing with its speed and handling long agentic tasks and multi-file reasoning without getting lost.

November 4, 2025 - When Anthropic calls Sonnet 4.5 their "smartest model," they're making a specific claim about reasoning capability, context understanding, and output quality. Let me break down what this actually means in practice: The most noticeable improvement is in complex reasoning tasks. When you ask Claude Sonnet 4.5 to analyze something multifaceted—a business problem with competing priorities, a philosophical question with multiple perspectives, a technical challenge requiring several steps—the depth of analysis is noticeably better than previous models.

September 29, 2025 - Claude Sonnet 4.5 demonstrates advancements in agent capabilities, with enhanced performance in tool handling, memory management, and context processing. The model shows marked improvements in code generation and analysis, from identifying optimal ...

September 30, 2025 - I get the impression that with this release, Anthropic is targeting enterprise customers, too. With an emphasis on coding for long stretches autonomously and better handling of science and finance tasks, there is a strong push for Claude Sonnet 4.5 to be the go-to model for complex coding tasks.

Claude Opus 4.5 excels at long-horizon, autonomous tasks, especially those that require sustained reasoning and multi-step execution. In our evaluations it handled complex workflows with fewer dead-ends. On Terminal Bench it delivered a 15% improvement over Sonnet 4.5, a meaningful gain that ...

October 7, 2025 - For creative outputs, Sonnet 4.5 is solid too – it matches or exceeds prior models (Claude Opus 4.1) on tasks like slide/animation generation and producing polished, well-designed content ([10]).

Claude Sonnet 4.5's edit capabilities are exceptional — we went from 9% error rate on Sonnet 4 to 0% on our internal code editing benchmark. Higher tool success at lower cost is a major leap for agentic coding.

September 29, 2025 - Claude Sonnet 4.5, released Monday, outperforms prior versions at coding, finance, cybersecurity and long-duration autonomous work, Anthropic said.

September 30, 2025 - If you already rely on Claude 3.5 for coding, research, or agentic workflows, the real question is whether 4.5 tangibly reduces rework and failures enough to justify an immediate upgrade. Below is a pragmatic, scenario-led comparison to help you decide. ... Pricing parity: Anthropic reiterated that Sonnet 4.5 keeps Sonnet-tier pricing at $3 per million input tokens and $15 per million output tokens in 2025 (see the Anthropic 4.5 announcement, 2025).

September 29, 2025 - ... Initial read indicates not much benchmark improvement, but enhancements on the agentic coding side of issues as well as efficiencies to keep pricing stable. ... Claude Sonnet 4.5 includes automatic optimizations to improve model performance.

October 2, 2025 - Claude Sonnet 4.5 review: it’s the model I’d pick for agentic systems and advanced coding tasks today. The combination of longer context, the Agent SDK, and better safety tooling makes it practical to build complex workflows faster.

August 22, 2025 - It's very good - I think probably a tiny bit better than GPT-5-Codex, based on vibes more than a comprehensive comparison (there are plenty of benchmarks out there that attempt to be more methodical than vibes) · It particularly shines when you try it on https://claude.ai/ using its brand ...

Sonnet 4 failed their rubric in many of these areas 20%-40% of the time, which seems unacceptably high, whereas with Sonnet 4.5 most areas are now below 5% failure rates, with especially notable improvement on biological and deadly weapons. It’s always interesting to see which concerns get tested, in particular here ‘romance scams.’ · For Claude Sonnet 4.5, our multi-turn testing covered the following risk areas: