Anthropic releases Claude Opus 4 and Sonnet 4
Claude Code goes GA
Confirmed
Importance: historic (5 of 5)The takeaway
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.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- Historic (5 of 5)
- Last verified
- 29 September 2026
Your AI and this story
- GPT-6 AstraIn its training data
- Claude Opus 5.5In its training data
- Gemini 4 HydrogenIn its training data
- Grok 4.7In its training data
It happened before the cutoffs of all four assistants, so it can be in their training data.
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.
Sources
3 sources from 1 site. Numbers match the chips in the text.
3 sources: 3 primary
Primary
- Introducing Claude 4 (Anthropic)anthropic.com, official
- Activating AI Safety Level 3 Protections (Anthropic)anthropic.com, official
- Claude Opus 4.1 (Anthropic)anthropic.com, official
Changes
- Filed