---
id: "2025-11-24-claude-opus-4-5"
url: "https://postcutoff.com/e/2025-11-24-claude-opus-4-5/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2025-11-24"
date_precision: day
category: model-release
importance: 4
confidence: high
status: [Confirmed]
sources: 5
editor: human editor
human_review: null
version: "2026-10-11"
---

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/2025-11-24-claude-opus-4-5/

# Anthropic releases Claude Opus 4.5

Claude Opus 4.5 set a new state of the art on SWE-bench Verified (80.9%) at a much lower price than prior Opus models, and Anthropic reported it scored higher than any human candidate ever on its take-home performance-engineering exam.

## Key facts
- Released 24 November 2025
- SWE-bench Verified: 80.9% (first model above 80%), per Anthropic's published results
- Scored higher than any human candidate ever on Anthropic's 2-hour performance-engineering take-home exam
- Price: $5 / $25 per million input/output tokens (down from $15 / $75)
- New 'effort' parameter to trade off speed and thoroughness

## What happened

Anthropic released its most capable model of 2025, emphasizing coding, agents and computer use.

## Why it matters

Made frontier-level agentic coding cheaper and helped drive rapid adoption of long-running coding agents at the end of 2025.

## 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. [Anthropic Engineering: Introducing advanced tool use on the Claude Developer Platform (Nov 24, 2025)](https://www.anthropic.com/engineering/advanced-tool-use) (anthropic.com, official)
2. [Anthropic Engineering: Effective harnesses for long-running agents (Nov 26, 2025)](https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents) (anthropic.com, official)
3. [Introducing Claude Opus 4.5 (Anthropic)](https://www.anthropic.com/news/claude-opus-4-5) (anthropic.com, official)
4. [Claude Opus (Anthropic product page)](https://www.anthropic.com/claude/opus) (anthropic.com, official)
5. [Wikipedia: Claude (language model)](https://en.wikipedia.org/wiki/Claude_(language_model)) (en.wikipedia.org, discussion)

## Changes

- 2026-10-11: Added related Anthropic engineering post link(s)
- 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)
- 2025-05-22: [Anthropic releases Claude Opus 4 and Sonnet 4](https://postcutoff.com/e/2025-05-22-claude-4/index.md)