Overview
- Anthropic released Sonnet 5.5 on Monday, Sept. 28, 2026, and says the mid‑tier model runs about 30% faster than Sonnet 5 while using fewer tokens to complete the same tasks.
- Sonnet 5.5 keeps Sonnet’s price at $2 per million input tokens and $10 per million output tokens and uses lower token burn to reduce customer bills for coding, document and spreadsheet work.
- Anthropic says Sonnet 5.5 has “comparable” cybersecurity capabilities to its higher‑tier Opus models and is the first Sonnet to receive the same cyber safeguards and fallbacks.
- The company reported that roughly 80% of revenue comes from enterprise clients, naming customers such as Salesforce, Databricks, Goldman Sachs and Novo Nordisk as target users for Sonnet 5.5.
- Sonnet 5.5 follows Opus 5.5’s launch last week and precedes a promised Haiku 5.5; independent scrutiny of Anthropic’s performance and safety claims continues and could shape customer adoption and regulatory interest.