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AnthropicProprietary
Claude Opus 4.5
Claude Opus 4.5 is a foundation model developed by Anthropic. It is positioned as a reasoning model with advanced reasoning capabilities and supports an extensive context window of 200K.
Parameters
Undisclosed
Context Window
200K
License
Proprietary
Release Date
2025-11-25
API Pricing
Input Price (per 1M tokens)
$2.5
Output Price (per 1M tokens)
$
Billing Mode: standard
Strengths
- ・Enables advanced reasoning
- ・Long 200K context window
- ・Uses latest architecture
Weaknesses
- ・Restricted by non-open-source license
- ・Closed-source license
- ・Detailed specs not fully public
Use Cases
- ・Complex logical reasoning
- ・Analyzing large documents
- ・Advanced problem-solving
Deep Analysis
Arena Elo
1468
#6 overall at launch
SWE-Bench Verified
72.8%
at launch (Sept 2025)
Input Price
$5/1M
same as Opus 4.7
Output Price
$25/1M
same as Opus 4.7
Context Window
200K tokens
vs Opus 4.7: 1M
Output Speed
50 tok/s
frontier tier
Strengths
- ・Strong coding performance at launch (SWE-bench Verified 72.8%)
- ・Excellent mathematical reasoning
- ・Mature ecosystem with broad tool support
- ・Same pricing as Opus 4.7 ($5/$25)
Weaknesses
- ・200K context window — smaller than competitors (1M+)
- ・Superseded by Opus 4.7 with significant improvements
- ・Extended thinking removed in favor of adaptive thinking
Competitor Comparison
| Model | Arena | SWE | GPQA | Price |
|---|---|---|---|---|
| Claude Opus 4.7 | ~1500 | 87.6% | 94.2% | $5/$25 |
| GPT-5.4 | 1467 | 80.8% | 94.4% | $2.50/$15 |
| Claude Opus 4.5 | 1468 | 72.8% | ~90% | $5/$25 |
Analysis generated: 2026-05-24