---
id: "2025-05-22-claude-4"
url: "https://postcutoff.com/e/2025-05-22-claude-4/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2025-05-22"
date_precision: day
category: model-release
importance: 5
confidence: high
status: [Confirmed]
sources: 3
editor: human editor
human_review: null
version: "2026-10-04"
---

As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/e/2025-05-22-claude-4/

# Anthropic releases Claude Opus 4 and Sonnet 4

Full title: 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.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): in its training data
- Claude Opus 5.5 (training cutoff June 2026): in its training data
- Gemini 4 Hydrogen (training cutoff March 2026): in its training data
- Grok 4.7 (training cutoff May 2026): in its training data

## Sources

1. [Introducing Claude 4 (Anthropic)](https://www.anthropic.com/news/claude-4) (anthropic.com, official)
2. [Activating AI Safety Level 3 Protections (Anthropic)](https://www.anthropic.com/news/activating-asl3-protections) (anthropic.com, official)
3. [Claude Opus 4.1 (Anthropic)](https://www.anthropic.com/news/claude-opus-4-1) (anthropic.com, official)

## Changes

- 2026-09-29 (filed): Created

## Related

- 2025-09-29: [Anthropic releases Claude Sonnet 4.5](https://postcutoff.com/e/2025-09-29-claude-sonnet-4-5/index.md)
- 2025-02-24: [Claude 3.7 Sonnet (hybrid reasoning) and Claude Code preview](https://postcutoff.com/e/2025-02-24-claude-3-7-sonnet-claude-code/index.md)