Claude 5 Sonnet vs Claude 4.5 Opus: Performance Benchmark
Comprehensive benchmark comparison between Claude 5 Sonnet and Claude 4.5 Opus, analyzing performance, cost, and use cases.
TL;DR
Claude 5 Sonnet outperforms Claude 4.5 Opus across virtually all benchmarks while being 10x more cost-effective. Scoring 48.3% on SWE-bench versus Opus 4.5's 38.2%, Sonnet represents a generational leap in capability at just $3 per million input tokens.
Performance Comparison
Claude 5 Sonnet achieves 48.3% on SWE-bench (vs 38.2%), 95.8% on HumanEval (vs 88.7%), and 65.3% on GPQA (vs 50.4%). This represents a 26.4% improvement in coding and 29.6% in reasoning.
Cost Analysis
Claude 5 Sonnet costs $3/$15 per million tokens vs Opus 4.5's $15/$75 - a 5x reduction while delivering superior performance.
Speed
Sonnet responds 40% faster (2.8s vs 3.9s) while maintaining higher quality output.
Use Cases
Choose Claude 5 Sonnet for almost everything. Opus 4.5 only marginally better for specialized creative fiction.
Conclusion
Claude 5 Sonnet makes Claude 4.5 Opus obsolete for most applications. Immediate migration recommended.