Claude Opus 4.5 is Anthropic's frontier reasoning model released in November 2025, optimized for complex software engineering, agentic workflows, and long-horizon computer use. It offers strong multimodal capabilities, improved robustness to prompt injection, and a new effort parameter that lets developers trade off speed, depth, and token usage depending on task requirements. The model excels at autonomous research, multi-step debugging, spreadsheet and browser manipulation, and coordinated multi-agent setups, delivering substantial gains in structured reasoning and execution reliability.
Anthropic ProAnthropic Max (5x)Anthropic Max (20x)API|VisionReasoningWeb SearchFile|Proprietary Model
Knowledge Cutoff
2025-08-01
Input → Output Format
Context Memory
200KIN64KOUT
AI Performance Evaluation
Arena Overall Score
1473
±4As of 2026-05-01
Overall Rank
No.17
37,158 Votes
Arena by Ability
Hard Prompts
1499±5No.10
Expert Knowledge
1504±13No.11
Instruction Following
1485±7No.6
Conversation Memory
1487±8No.12
Creative
1468±9No.7
Coding
1531±7No.5
Math
1470±12No.18
Arena by Occupation
Creative Writing
1465±7No.10
Social Sciences
1488±8No.15
Media
1456±8No.9
Business
1468±8No.21
Healthcare
1488±13No.19
Legal
1486±12No.15
Software
1513±6No.9
Mathematics
1470±15No.23
Source:Arena Intelligence
Overall
AA Intelligence Index
50%↑11%
LiveBench
54%↓7%
ForecastBench
60%↑1%
Reasoning & Math
AA Math Index
91%↑17%
GPQA Diamond
87%↑4%
HLE
28%↑11%
MMLU-Pro
90%↑8%
AIME 2025
91%↑17%
LB Reasoning
48%↓21%
LB Math
64%↓10%
LB Data
44%↓9%
Coding
AA Coding Index
48%↑11%
LiveCodeBench
87%↑22%
LB Coding
78%↑5%
LB Agentic
50%↑5%
TAU2
90%↑9%
TerminalBench
47%↑13%
SciCode
50%↑8%
Language & Instructions
IFBench
58%↓5%
AA-LCR
74%↑12%
Hallucination (HHEM)
11%↑1%
Factual (HHEM)
89%↓1%
LB Language
77%↑5%
LB IF
29%↓22%
Output Speed
Standard Mode
51tok/s↓26
First Output 1.21s
Reasoning Mode
58tok/s↓28
First Output 13.53s
