Anthropic releases Claude Opus 4 and Sonnet 4; Claude Code goes GA
Claude Opus 4 and Sonnet 4 led coding benchmarks and could work autonomously for hours; Opus 4 was the first model Anthropic deployed under its stricter ASL-3 safety standard, and Claude Code became generally available.
Key facts
- Released 22 May 2025
- SWE-bench Verified: Opus 4 72.5%, Sonnet 4 72.7%, per Anthropic
- Opus 4 deployed with ASL-3 protections under the Responsible Scaling Policy
- Claude Code generally available with VS Code and JetBrains integrations
- Claude Opus 4.1 followed on 5 August 2025 (74.5% SWE-bench Verified)
What happened
Anthropic launched its fourth-generation models focused on long-running agentic coding tasks.
Why it matters
Cemented Claude's lead in coding agents and was the first frontier deployment under elevated safeguards for CBRN risk.
Changelog
- 2026-09-29: created
Related events
- Claude 3.7 Sonnet (hybrid reasoning) and Claude Code preview ★★★★
- Anthropic releases Claude Sonnet 4.5 ★★★★
- Anthropic releases Claude Opus 4.5 ★★★★
Sources (3)
- officialIntroducing Claude 4 (Anthropic)
- officialActivating AI Safety Level 3 Protections (Anthropic)
- officialClaude Opus 4.1 (Anthropic)
id: 2025-05-22-claude-4 · updated 2026-09-29 · open in the interactive timeline