Claude 3.5 Sonnet

Claude 3.5 Sonnet is a large language model created by Anthropic, released June 20, 2024. It was later followed by Claude Sonnet 3.6 in October, which was originally called “Claude 3.5 Sonnet (new)” or “the upgraded Claude 3.5 Sonnet”.

Sonnet 3.5 was deprecated on August 13, 2025 and retired on October 28, 2025.

Details

  • Launched alongside Artifacts in the Claude.ai interface.
  • Same 200K context as Claude 3, with max output raised to 8,192 tokens.
  • Priced identically to Claude 3 Sonnet ($3 / $15 per million tokens) while substantially outperforming Claude 3 Opus on Anthropic’s reported benchmarks.
  • The October 22, 2024 “upgraded Claude 3.5 Sonnet” — colloquially Sonnet 3.6 — shipped under the same family but a new snapshot.

Further reading