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Claude Sonnet 5.5 vs Opus 5.5: Half the Price, Nearly the Same Scores — and a Routing Trap

· Aleksei Aleinikov · Sept. 29, 2026, 6:54 a.m.
claude-sonnet-5-5 claude-opus-5-5 anthropic-pricing llm-model-routing software development benchmarking Cost Analysis Product Comparison
Summary
This blog post compares two products, Claude Sonnet 5.5 and Opus 5.5, analyzing their performance benchmarks, price differences, and key changes from a previous version. It highlights how cost savings can diminish under maximum effort usage and addresses a technical issue with a router that affects the models' capabilities.
Read full post on www.alekseialeinikov.com →
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