Compare · ModelsLive · 3 picked · head to head
Claude Opus 5.5 vs Claude Sonnet 5.5 vs GPT-6 Astra
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
Claude Opus 5.5 wins on 14/24 benchmarks
Claude Opus 5.5 wins 14 of 24 shared benchmarks. Leads in speed · coding · general.
Category leads
speed·Claude Opus 5.5agentic·Claude Sonnet 5.5coding·Claude Opus 5.5math·GPT-6 Astrageneral·Claude Opus 5.5knowledge·GPT-6 Astrareasoning·GPT-6 Astra
Hype vs Reality
Attention vs performance
Claude Opus 5.5
#3 by perf·#9 by attention
Claude Sonnet 5.5
#11 by perf·#10 by attention
GPT-6 Astra
#9 by perf·#1 by attention
Best value
Claude Sonnet 5.5
1.8x better value than Claude Opus 5.5
Claude Opus 5.5
6.9 pts/$
$12.00/M
Claude Sonnet 5.5
12.5 pts/$
$6.00/M
GPT-6 Astra
2.6 pts/$
$30.00/M
Vendor risk
Who is behind the model
Anthropic
$965.0B·Tier 1
Anthropic
$965.0B·Tier 1
OpenAI
$840.0B·Tier 1
Head to head
24 benchmarks · 3 models
Claude Opus 5.5Claude Sonnet 5.5GPT-6 Astra
Artificial Analysis · CritPt
Claude Opus 5.5
31.7
Claude Sonnet 5.5
31.4
GPT-6 Astra
31.7
Artificial Analysis · GDPval
Claude Opus 5.5 leads by +0.3
Claude Opus 5.5
67.3
Claude Sonnet 5.5
67.0
GPT-6 Astra
52.1
Artificial Analysis · Humanity's Last Exam
Claude Opus 5.5 leads by +6.4
Claude Opus 5.5
61.4
Claude Sonnet 5.5
55.0
GPT-6 Astra
54.7
Artificial Analysis · Long Context Reasoning
Claude Opus 5.5 leads by +2.0
Claude Opus 5.5
84.7
Claude Sonnet 5.5
82.7
GPT-6 Astra
80.7
Artificial Analysis · Quality Index
Claude Opus 5.5 leads by +1.6
Claude Opus 5.5
57.6
Claude Sonnet 5.5
56.0
GPT-6 Astra
52.7
Artificial Analysis · SciCode
Claude Opus 5.5 leads by +5.9
Claude Opus 5.5
66.9
Claude Sonnet 5.5
61.0
GPT-6 Astra
56.5
APEX-Agents
Claude Sonnet 5.5 leads by +2.0
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
Claude Sonnet 5.5
75.5
GPT-6 Astra
64.7
Frontiercode
Claude Opus 5.5 leads by +1.4
Claude Opus 5.5
54.6
Claude Sonnet 5.5
52.1
GPT-6 Astra
53.3
FrontierMath-Tier-4-v2-Private
GPT-6 Astra leads by +2.6
Claude Opus 5.5
95.0
Claude Sonnet 5.5
80.5
GPT-6 Astra
97.6
FrontierMath-Tiers-1-3-v2-Private
GPT-6 Astra leads by +2.5
Claude Opus 5.5
91.2
Claude Sonnet 5.5
88.8
GPT-6 Astra
93.7
Frontierswe
GPT-6 Astra leads by +3.2
Claude Opus 5.5
62.3
Claude Sonnet 5.5
61.9
GPT-6 Astra
65.5
Furniture Assembly
Claude Opus 5.5 leads by +4.8
Claude Opus 5.5
76.2
Claude Sonnet 5.5
64.3
GPT-6 Astra
71.4
GPQA diamond
GPT-6 Astra leads by +0.3
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
87.5
Claude Sonnet 5.5
94.1
GPT-6 Astra
94.4
Mystery Game Puzzles
GPT-6 Astra leads by +14.3
Claude Opus 5.5
68.0
Claude Sonnet 5.5
61.5
GPT-6 Astra
82.4
OTIS Mock AIME 2024-2025
OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills.
Claude Opus 5.5
100.0
Claude Sonnet 5.5
100.0
GPT-6 Astra
100.0
Proofbench
Claude Opus 5.5
100.0
Claude Sonnet 5.5
100.0
GPT-6 Astra
99.0
SimpleQA Verified
GPT-6 Astra leads by +3.4
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
Claude Sonnet 5.5
46.5
GPT-6 Astra
75.6
Artificial Analysis · MMMU Pro
Claude Opus 5.5 leads by +0.8
Claude Opus 5.5
87.7
GPT-6 Astra
86.9
ARC-AGI
GPT-6 Astra leads by +1.0
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
Claude Opus 5.5
97.5
GPT-6 Astra
98.5
ARC-AGI-2
GPT-6 Astra leads by +2.5
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
92.5
GPT-6 Astra
95.0
Dtbench
Claude Opus 5.5 leads by +2.7
Claude Opus 5.5
98.2
GPT-6 Astra
95.5
Ebr Bench
GPT-6 Astra leads by +4.8
Claude Opus 5.5
71.4
GPT-6 Astra
76.2
Lmca
Claude Opus 5.5 leads by +4.5
Claude Opus 5.5
80.3
GPT-6 Astra
75.7
Mirrorcode
Claude Opus 5.5 leads by +30.7
Claude Opus 5.5
77.4
GPT-6 Astra
46.7
Full benchmark table
| Benchmark | Claude Opus 5.5 | Claude Sonnet 5.5 | GPT-6 Astra |
|---|---|---|---|
Artificial Analysis · CritPt | 31.7 | 31.4 | 31.7 |
Artificial Analysis · GDPval | 67.3 | 67.0 | 52.1 |
Artificial Analysis · Humanity's Last Exam | 61.4 | 55.0 | 54.7 |
Artificial Analysis · Long Context Reasoning | 84.7 | 82.7 | 80.7 |
Artificial Analysis · Quality Index | 57.6 | 56.0 | 52.7 |
Artificial Analysis · SciCode | 66.9 | 61.0 | 56.5 |
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 | 75.5 | 64.7 |
Frontiercode | 54.6 | 52.1 | 53.3 |
FrontierMath-Tier-4-v2-Private | 95.0 | 80.5 | 97.6 |
FrontierMath-Tiers-1-3-v2-Private | 91.2 | 88.8 | 93.7 |
Frontierswe | 62.3 | 61.9 | 65.5 |
Furniture Assembly | 76.2 | 64.3 | 71.4 |
GPQA diamond Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs. | 87.5 | 94.1 | 94.4 |
Mystery Game Puzzles | 68.0 | 61.5 | 82.4 |
OTIS Mock AIME 2024-2025 OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills. | 100.0 | 100.0 | 100.0 |
Proofbench | 100.0 | 100.0 | 99.0 |
SimpleQA Verified SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information. | 72.2 | 46.5 | 75.6 |
Artificial Analysis · MMMU Pro | 87.7 | — | 86.9 |
ARC-AGI ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization. | 97.5 | — | 98.5 |
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. | 92.5 | — | 95.0 |
Dtbench | 98.2 | — | 95.5 |
Ebr Bench | 71.4 | — | 76.2 |
Lmca | 80.3 | — | 75.7 |
Mirrorcode | 77.4 | — | 46.7 |
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 | |
| $2.00 | $10.00 | 1.0M tokens (~500 books) | $40.00 | |
| $10.00 | $50.00 | 1.1M tokens (~525 books) | $200.00 |