Compare · ModelsLive · 2 picked · head to head
Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
Claude Opus 5.5 wins on 10/11 benchmarks
Claude Opus 5.5 wins 10 of 11 shared benchmarks. Leads in agentic · reasoning · knowledge.
Category leads
agentic·Claude Opus 5.5reasoning·Claude Opus 5.5knowledge·Claude Opus 5.5math·Claude Opus 5.5general·Claude Opus 5.5
Hype vs Reality
Attention vs performance
Claude Opus 5.5
#10 by perf·#5 by attention
DeepSeek V4.1 Flash 1017
#41 by perf·#4 by attention
Best value
DeepSeek V4.1 Flash 1017
41.2x better value than Claude Opus 5.5
Claude Opus 5.5
6.2 pts/$
$12.00/M
DeepSeek V4.1 Flash 1017
254.9 pts/$
$0.25/M
Vendor risk
Mixed exposure
One or more vendors flagged
Anthropic
$965.0B·Tier 1
DeepSeek
$3.4B·Tier 1
Head to head
11 benchmarks · 2 models
Claude Opus 5.5DeepSeek V4.1 Flash 1017
APEX-Agents
Claude Opus 5.5 leads by +3.7
APEX-Agents · evaluates AI agents on complex, multi-step tasks requiring planning, tool use, and autonomous decision-making in realistic environments.
Claude Opus 5.5
73.5
DeepSeek V4.1 Flash 1017
69.8
ARC-AGI
Claude Opus 5.5 leads by +4.0
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
Claude Opus 5.5
98.5
DeepSeek V4.1 Flash 1017
94.5
ARC-AGI-2
Claude Opus 5.5 leads by +15.3
ARC-AGI-2 · the second iteration of the Abstraction and Reasoning Corpus, testing novel pattern recognition and abstract reasoning without prior training data.
Claude Opus 5.5
93.3
DeepSeek V4.1 Flash 1017
78.1
Chess Puzzles
Claude Opus 5.5 leads by +22.1
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
Claude Opus 5.5
65.3
DeepSeek V4.1 Flash 1017
43.2
FrontierMath-Tier-4-v2-Private
Claude Opus 5.5 leads by +48.7
Claude Opus 5.5
95.0
DeepSeek V4.1 Flash 1017
46.3
FrontierMath-Tiers-1-3-v2-Private
Claude Opus 5.5 leads by +21.0
Claude Opus 5.5
96.0
DeepSeek V4.1 Flash 1017
75.0
GPQA diamond
DeepSeek V4.1 Flash 1017 leads by +3.6
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Claude Opus 5.5
91.1
DeepSeek V4.1 Flash 1017
94.7
Mystery Game Puzzles
Claude Opus 5.5 leads by +24.2
Claude Opus 5.5
68.0
DeepSeek V4.1 Flash 1017
43.8
OTIS Mock AIME 2024-2025
Claude Opus 5.5 leads by +0.6
OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills.
Claude Opus 5.5
100.0
DeepSeek V4.1 Flash 1017
99.4
SimpleQA Verified
Claude Opus 5.5 leads by +29.7
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
Claude Opus 5.5
72.2
DeepSeek V4.1 Flash 1017
42.5
WeirdML v3
Claude Opus 5.5 leads by +33.2
Claude Opus 5.5
55.4
DeepSeek V4.1 Flash 1017
22.1
Full benchmark table
| Benchmark | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
APEX-Agents APEX-Agents · evaluates AI agents on complex, multi-step tasks requiring planning, tool use, and autonomous decision-making in realistic environments. | 73.5 | 69.8 |
ARC-AGI ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization. | 98.5 | 94.5 |
ARC-AGI-2 ARC-AGI-2 · the second iteration of the Abstraction and Reasoning Corpus, testing novel pattern recognition and abstract reasoning without prior training data. | 93.3 | 78.1 |
Chess Puzzles Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities. | 65.3 | 43.2 |
FrontierMath-Tier-4-v2-Private | 95.0 | 46.3 |
FrontierMath-Tiers-1-3-v2-Private | 96.0 | 75.0 |
GPQA diamond Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs. | 91.1 | 94.7 |
Mystery Game Puzzles | 68.0 | 43.8 |
OTIS Mock AIME 2024-2025 OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills. | 100.0 | 99.4 |
SimpleQA Verified SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information. | 72.2 | 42.5 |
WeirdML v3 | 55.4 | 22.1 |
Pricing · per 1M tokens · projected $/mo at 10M tokens
| Model | Input | Output | Context | Projected $/mo |
|---|---|---|---|---|
| $4.00 | $20.00 | 1.0M tokens (~500 books) | $80.00 | |
| $0.01 | $0.50 | 1.0M tokens (~524 books) | $1.29 |