Anthropic's Claude Sonnet 5.5 nears Opus 5.5 at half the price

Anthropic released Claude Sonnet 5.5 on September 28, 2026, priced at $2 per million input tokens and $10 per million output tokens — half the cost of flagship Opus 5.5. It generates output over 30% faster than Sonnet 5 and beats Opus 5.5 on Terminal-Bench 4.0 with a score of 70.6%.

• Pricing: $2 per million input and $10 per million output tokens, half of Opus 5.5
• Terminal-Bench 4.0: 70.6% vs 66.4% for Opus 5.5 and 10.3% for Sonnet 5
• 1M-token context window, 128,000 max output, June 2026 knowledge cutoff
• Sonnet 4.5 retires November 30, 2026; replacement is claude-sonnet-5-5