Claude Opus 4.5 - Proven Performer

Claude Opus 4.5 is a strong model for coding and reasoning tasks. It delivers excellent performance on software engineering benchmarks with good token efficiency. Note: Claude Opus 4.7 is the latest generation with 13% better coding performance and significantly improved capabilities—we recommend it for new projects.

Why Choose Claude Opus 4.5?

Perfect for:

• Long-horizon autonomous coding tasks
• Complex multi-step reasoning and planning
• Code refactoring across multiple codebases
• Enterprise applications with sophisticated requirements
• Production code that requires reliability and precision

Real User Experiences:

"Claude Opus 4.5 handles long-horizon coding tasks more efficiently than any model we've tested. It achieves higher pass rates on held-out tests while using up to 65% fewer tokens." - Sean Ward, CEO Sweep

"Claude Opus 4.5 delivered an impressive refactor. It was very thorough, helping develop a robust plan, handling the details and fixing tests." - Paulo Arruda, Staff Engineer at Slack

"At medium effort level, Opus 4.5 matches Sonnet 4.5's best score on SWE-bench Verified, but uses 76% fewer output tokens." - Anthropic Engineering

What You Get

• State-of-the-Art Coding: Leads across 7 out of 8 programming languages on SWE-bench Multilingual
• Token Efficiency: Uses 48-76% fewer tokens than Sonnet 4.5 while matching or exceeding quality
• Advanced Planning: Excels at building precise plans and executing multi-step tasks
• Creative Problem Solving: Finds insightful, legitimate solutions to complex problems

Cost

Official Rates: $5 per 1M input tokens / $25 per 1M output tokens

Typical costs: ~$0.50 for a landing page, ~$2 for a small app, ~$5 for a complex build. Now at a price point where Opus can be your go-to model for most tasks, with dramatically better efficiency than previous Opus versions.

Technical Capabilities

• Effort Control: New parameter lets you balance speed/cost vs. capability
• Extended Thinking: 64K thinking budget for complex reasoning
• 200K Context Window: Handles large codebases and complex requirements
• Advanced Tool Use: Better at handling long-running agentic tasks
• Fewer Iterations: Requires fewer steps to solve tasks with more precise execution

Performance Highlights

SWE-bench Verified Leadership: State-of-the-art on real-world software engineering tests

Token Efficiency:

• At medium effort: Matches Sonnet 4.5 quality with 76% fewer output tokens
• At high effort: Beats Sonnet 4.5 by 4.3 points with 48% fewer tokens

Real-World Impact:

• 50-75% reduction in tool calling errors and build/lint errors
• 15% improvement on Terminal Bench over Sonnet 4.5
• Consistent performance across long multi-step sessions

Building Web Apps with Claude Opus 4.5 on Softgen

The 48-76% token efficiency matters on Softgen: same Opus-tier refactor at lower session cost. The agent runs multi-file changes efficiently, tracks progress on the tasks board, and leads 7 of 8 languages on SWE-bench Multilingual.

For new projects, 4.7 is better. Opus 4.5 still earns its slot on long-running sessions where its token efficiency (48-76% fewer output tokens than Sonnet 4.5) means lower total spend.

When to Use a Different Model

• Simple landing pages (try Gemini 3.1 Pro)
• Rapid iteration on simple concepts (try GPT 5.4)
• When you need the absolute fastest speed over quality (try Haiku 4.5)

The Bottom Line

Claude Opus 4.5 is a solid choice for complex coding tasks with good efficiency. However, Claude Opus 4.7 is now the recommended model with 13% better coding performance, 3× better production task resolution, and superior vision capabilities.

Choose Opus 4.5 when you need:

• Reliable coding execution with good consistency
• Cost-effective reasoning for multi-step tasks
• Enterprise stability with proven performance

Best for: Existing workflows, token-efficient production sessions, and scenarios where you prefer a proven previous-generation model. For new projects, consider Opus 4.7.

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Want to learn more? Read the official Claude Opus 4.5 announcement from Anthropic for technical benchmarks and capabilities.