Anthropic Claude Opus 4.5 Review - Performance, Pricing, and Real World Benchmarks

Introduction

Anthropic has just released Claude Opus 4.5, its newest flagship model aimed at coding, autonomous agents, and real‑world computer use. Positioned as a direct competitor to Google’s Gemini 3 Pro, Opus 4.5 promises not only higher performance on technical tasks but also a considerably lower price point. In this article we break down the model’s pricing, benchmark results, and real‑world testing to see whether Opus 4.5 lives up to the hype.

Pricing and Cost Efficiency

One of the most notable changes with Opus 4.5 is the dramatic reduction in token costs:

• Input tokens: $5 per million (down from $15)
• Output tokens: $25 per million (down from $75)

This pricing shift makes the model far more accessible for daily workloads, especially for developers who need to keep API usage affordable. Anthropic also provides guidance on reducing context length to further trim costs, highlighting a focus on practical, cost‑conscious deployments.

Benchmark Performance

Coding Benchmarks

Opus 4.5 shows impressive gains across a variety of coding evaluations:

• Ader Polyglot: 89.4% success vs. Sonnet 4.5’s 78.8%
• Aentic Coding SBench: 80.9% vs. Sonnet 4.5’s 77.2% and Opus 4.1’s 74.5%
• Terminal Bench 2.0: 59.3% (up from Opus 4.1’s 46.5%)
• Multilingual Coding (C, Go, Java, JS/TS, PHP, Ruby, Rust): Opus 4.5 leads Sonnet 4.5 and Opus 4.1 with higher pass rates and tighter error bars.

Agentic and Long‑Term Coherence Benchmarks

• Vending Bench (long‑run coherence): Cost rises from $3,849.74 (Sonnet 4.5) to $4,967.6 for Opus 4.5, indicating stable performance over extended runs.
• Browse‑Comp‑Plus: 72.9% success vs. Sonnet 4.5’s 67.2% when paired with tool result clearing, memory, and context resetting.

Safety and Robustness

Safety metrics also improve:

• Concerning behavior: Drops to ~10% for Opus 4.5, lower than Sonnet 4.5 and competing Frontier models.
• Prompt injection susceptibility (K=1): 4.7% for Opus 4.5 vs. 7.3% for Sonnet 4.5; remains the lowest across tested models.

Reasoning and General Intelligence

Outside pure coding, Opus 4.5 remains competitive on heavy‑reasoning tasks:

• ARC‑AI2: 37.6% (a large jump over Sonnet’s 13.6%)
• GPQA‑Diamond: 87.0%
• Visual Reasoning (MMU‑Val): 80.7%

Real‑World Testing

Non‑Agentic Tasks

The model was asked to generate a variety of creative outputs:

• Floor plan: Functional but not optimal.
• SVG of a panda holding a burger: Low‑quality output.
• Pokéball in Three.js: Acceptable, though background could be improved.
• Chessboard with autoplay: Failed to function.
• Minecraft‑style scene in Kandinsky style: Very high quality, one of the best generations observed.
• Butterfly simulation: Realistic physics and impressive visual fidelity.
• Rust CI tool and Blender script: Both produced solid, usable code.
• Math and riddle questions: Correctly answered, contributing to a 74% score on general reasoning tests—still below Gemini 3 Pro’s checkpoints.

Agentic Benchmarks

Using the Kilo Code interface (which integrates Claude models seamlessly), Opus 4.5 excelled in several end‑to‑end development tasks:

• Expo movie‑tracker app (TMDB API): Generated a fully functional UI with navigation and data handling.
• Go terminal calculator (Bubble Tea): Produced clean, working code.
• “Godo” game prototype: Functional but UI elements (health bar, step counter) were poorly placed.
• Open‑source repository modification: Added an SVG command in a single, accurate edit.
• Spelt task‑management app: Implemented login, board creation, SQLite storage, and full CRUD functionality.
• Next.js and Tari applications: Both ran without major issues.

These results placed Opus 4.5 at the top of the Agentic leaderboard.

Comparison with Gemini 3

While Opus 4.5 delivers superior backend and debugging capabilities, its front‑end output still lags behind Gemini 3, which consistently produces cleaner UI designs (e.g., fewer “purple” UI artifacts). A practical workflow could involve:

1. Use Opus 4.5 for backend logic, API integration, and complex algorithmic work.
2. Switch to Gemini 3 for polishing front‑end components and visual design.

Cost considerations are also significant. Gemini 3 achieves a 71.4% score for roughly $8, whereas Opus 4.5 reaches 77.1% at about $48. The performance boost comes with a higher price tag, making Opus 4.5 best suited for scenarios where budget is less constrained and top‑tier results are required.

Strengths and Limitations

Strengths

• Exceptional coding accuracy across multiple languages.
• Strong agentic performance for end‑to‑end development tasks.
• Improved safety and robustness metrics.
• Lower token pricing compared to previous Opus versions.

Limitations

• Front‑end generation still produces sub‑optimal UI aesthetics.
• Higher overall cost relative to competing models like Gemini 3.
• Certain creative outputs (e.g., SVG graphics) remain inconsistent.

Conclusion

Claude Opus 4.5 marks a substantial leap for Anthropic, delivering state‑of‑the‑art coding proficiency, solid agentic capabilities, and enhanced safety—all at a more affordable token price than its predecessors. While its front‑end output and cost per performance still trail behind Gemini 3, Opus 4.5 excels in backend development and complex reasoning tasks. For developers and organizations that prioritize robust backend generation and are willing to invest in top‑tier performance, Opus 4.5 is a compelling choice. Pairing it with a front‑end‑focused model like Gemini 3 could provide a balanced, cost‑effective workflow for full‑stack development.