This page may contain stale information. Last updated: 2026-07-01

Overview

Claude Sonnet 5 is anthropic’s mid-tier frontier model released June 30, 2026, succeeding claude-sonnet-4-6. Positioned as the most agentic Sonnet model — planning, browser/terminal tool use, and autonomous coding at near-claude-opus-4-8 performance at lower cost.

Specifications

  • API identifier: claude-sonnet-5
  • Default availability: Free and Pro plans; Max, Team, Enterprise; claude-code
  • Tokenizer: New tokenizer — ~30% more tokens for same text vs Sonnet 4.6 (2026-06-30-anthropic-claude-sonnet-5-datacamp)
  • Intro pricing (through Aug 31, 2026): 10/M output tokens
  • Standard pricing: 15/M output tokens

Benchmarks (Anthropic-reported)

BenchmarkSonnet 5Opus 4.8Sonnet 4.6
Agentic coding63.2%69.2%58.1%
Knowledge work~matches Opusbaselinelower

Anthropic corrected initial BrowseComp cost-performance chart methodology error June 30 ( 2026-06-30-anthropic-claude-sonnet-5-launch).

Safety Profile

  • Lower misalignment/desirable-behavior rate than Sonnet 4.6
  • Much lower offensive cybersecurity capability than Opus/Mythos
  • Better prompt-injection resistance and refusal consistency (Lovable cited)

Recent Developments

Sources