Anthropic's Claude Sonnet 5.5 nearly matches Opus 5.5 on benchmarks while costing up to 30 percent less per task
Sonnet 5.5 cuts costs 30% while nearly matching Opus on benchmarks—the efficiency tier just got competitive.
Why it matters
Anthropic's mid-tier model now delivers near-flagship performance at lower cost and faster speed, reshaping the price-to-capability curve and forcing buyers to reconsider their tier selection. This is a direct response to OpenAI's GPT-6 family scaling.
The key facts
6 to knowClaude Sonnet 5.5 released; Haiku 5.5 coming soon—completing Anthropic's answer to GPT-6 trio
Output speed: 30% faster than prior Sonnet version
Cost: up to 30% less per task than Opus 5.5
Benchmark performance: nearly matches Opus 5.5 on knowledge-work benchmarks
Coding benchmark (Terminal-Bench): 10.3% → 70.6% jump
Positioned as efficiency alternative to flagship Opus 5.5
Go to the source
The Decoderthe-decoder.com
Publisher excerpt: Anthropic has released Claude Sonnet 5.5, the second model in its Claude 5.5 family. It generates output more than 30 percent faster, costs up to 30 percent less per task, and nearly matches Opus 5.5 on knowledge-work benchmarks. On Terminal-Bench, a coding benchmark, the model jumps from 10.3 to…