Compare · ModelsLive · 3 picked · head to head

Claude Fable 5.1 vs Claude Mythos Preview vs GPT-6 Astra

Side by side · benchmarks, pricing, and signals you can act on.

Winner summary

GPT-6 Astra wins 15 of 28 shared benchmarks. Leads in reasoning · general · coding.

Category leads
knowledge·Claude Mythos Previewspeed·Claude Fable 5.1agentic·Claude Fable 5.1reasoning·GPT-6 Astrageneral·GPT-6 Astracoding·GPT-6 Astramath·GPT-6 Astra
Hype vs Reality
Claude Fable 5.1
#16 by perf·#12 by attention
UNDERRATED
Claude Mythos Preview
#5 by perf·no signal
QUIET
GPT-6 Astra
#9 by perf·#1 by attention
DESERVED
Best value
1.1x better value than Claude Fable 5.1
Claude Fable 5.1
2.4 pts/$
$30.00/M
Claude Mythos Preview
n/a
no price
GPT-6 Astra
2.6 pts/$
$30.00/M
Vendor risk
Anthropic logo
Anthropic
$965.0B·Tier 1
Medium risk
Anthropic logo
Anthropic
$965.0B·Tier 1
Medium risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Head to head
Claude Fable 5.1Claude Mythos PreviewGPT-6 Astra
HLE
Claude Mythos Preview leads by +4.3
HLE (Humanity's Last Exam) · a reasoning benchmark designed to be the hardest public evaluation of AI. Questions span mathematics, physics, philosophy, and logic · curated to be at or beyond the frontier of human expert capability. Tested with and without tool augmentation. Claude Opus 4.7 scores 46.9% without tools and 54.7% with tools · making it one of the few benchmarks where the top score is below 60%.
Claude Fable 5.1
43.8
Claude Mythos Preview
56.8
GPT-6 Astra
52.5
Artificial Analysis · CritPt
GPT-6 Astra leads by +2.0
Claude Fable 5.1
29.7
GPT-6 Astra
31.7
Artificial Analysis · GDPval
Claude Fable 5.1 leads by +9.6
Claude Fable 5.1
61.7
GPT-6 Astra
52.1
Artificial Analysis · GPQA Diamond
GPT-6 Astra leads by +2.4
Claude Fable 5.1
93.7
GPT-6 Astra
96.1
Artificial Analysis · Humanity's Last Exam
Claude Fable 5.1 leads by +4.4
Claude Fable 5.1
59.1
GPT-6 Astra
54.7
Artificial Analysis · Long Context Reasoning
Claude Fable 5.1 leads by +4.6
Claude Fable 5.1
85.3
GPT-6 Astra
80.7
Artificial Analysis · Quality Index
Claude Fable 5.1 leads by +0.7
Claude Fable 5.1
53.4
GPT-6 Astra
52.7
Artificial Analysis · SciCode
Claude Fable 5.1 leads by +6.6
Claude Fable 5.1
63.1
GPT-6 Astra
56.5
APEX-Agents
Claude Fable 5.1 leads by +3.9
APEX-Agents · evaluates AI agents on complex, multi-step tasks requiring planning, tool use, and autonomous decision-making in realistic environments.
Claude Fable 5.1
68.6
GPT-6 Astra
64.7
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 Fable 5.1
97.5
GPT-6 Astra
98.5
ARC-AGI-2
GPT-6 Astra leads by +5.0
ARC-AGI-2 · the second iteration of the Abstraction and Reasoning Corpus, testing novel pattern recognition and abstract reasoning without prior training data.
Claude Fable 5.1
90.0
GPT-6 Astra
95.0
Chess Puzzles
GPT-6 Astra leads by +26.3
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
Claude Fable 5.1
44.2
GPT-6 Astra
70.5
Dtbench
Claude Fable 5.1 leads by +0.5
Claude Fable 5.1
96.0
GPT-6 Astra
95.5
Ebr Bench
GPT-6 Astra leads by +19.0
Claude Fable 5.1
57.1
GPT-6 Astra
76.2
Frontiercode
GPT-6 Astra leads by +2.4
Claude Fable 5.1
50.9
GPT-6 Astra
53.3
FrontierMath-Tier-4-v2-Private
GPT-6 Astra leads by +9.8
Claude Fable 5.1
87.8
GPT-6 Astra
97.6
FrontierMath-Tiers-1-3-v2-Private
GPT-6 Astra leads by +3.5
Claude Fable 5.1
90.2
GPT-6 Astra
93.7
Frontierswe
GPT-6 Astra leads by +9.2
Claude Fable 5.1
56.3
GPT-6 Astra
65.5
Furniture Assembly
GPT-6 Astra leads by +14.3
Claude Fable 5.1
57.1
GPT-6 Astra
71.4
GPQA diamond
Claude Mythos Preview leads by +0.1
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Claude Mythos Preview
94.5
GPT-6 Astra
94.4
Lmca
Claude Fable 5.1 leads by +1.3
Claude Fable 5.1
77.0
GPT-6 Astra
75.7
Mirrorcode
Claude Fable 5.1 leads by +26.6
Claude Fable 5.1
73.3
GPT-6 Astra
46.7
Mystery Game Puzzles
GPT-6 Astra leads by +28.6
Claude Fable 5.1
53.7
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 Fable 5.1
100.0
GPT-6 Astra
100.0
Proofbench
Claude Fable 5.1 leads by +1.0
Claude Fable 5.1
100.0
GPT-6 Astra
99.0
Remote Labor Index
GPT-6 Astra leads by +2.9
Claude Fable 5.1
17.9
GPT-6 Astra
20.8
SimpleQA Verified
GPT-6 Astra leads by +4.8
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
Claude Fable 5.1
70.8
GPT-6 Astra
75.6
WeirdML
GPT-6 Astra leads by +0.7
WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns.
Claude Fable 5.1
92.9
GPT-6 Astra
93.6
Full benchmark table
BenchmarkClaude Fable 5.1Claude Mythos PreviewGPT-6 Astra
HLE
HLE (Humanity's Last Exam) · a reasoning benchmark designed to be the hardest public evaluation of AI. Questions span mathematics, physics, philosophy, and logic · curated to be at or beyond the frontier of human expert capability. Tested with and without tool augmentation. Claude Opus 4.7 scores 46.9% without tools and 54.7% with tools · making it one of the few benchmarks where the top score is below 60%.
43.856.852.5
Artificial Analysis · CritPt
29.7—31.7
Artificial Analysis · GDPval
61.7—52.1
Artificial Analysis · GPQA Diamond
93.7—96.1
Artificial Analysis · Humanity's Last Exam
59.1—54.7
Artificial Analysis · Long Context Reasoning
85.3—80.7
Artificial Analysis · Quality Index
53.4—52.7
Artificial Analysis · SciCode
63.1—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.
68.6—64.7
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.
90.0—95.0
Chess Puzzles
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
44.2—70.5
Dtbench
96.0—95.5
Ebr Bench
57.1—76.2
Frontiercode
50.9—53.3
FrontierMath-Tier-4-v2-Private
87.8—97.6
FrontierMath-Tiers-1-3-v2-Private
90.2—93.7
Frontierswe
56.3—65.5
Furniture Assembly
57.1—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.
—94.594.4
Lmca
77.0—75.7
Mirrorcode
73.3—46.7
Mystery Game Puzzles
53.7—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
Proofbench
100.0—99.0
Remote Labor Index
17.9—20.8
SimpleQA Verified
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
70.8—75.6
WeirdML
WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns.
92.9—93.6
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
Anthropic logoClaude Fable 5.1$10.00$50.001.0M tokens (~500 books)$200.00
Anthropic logoClaude Mythos Preview——1.0M tokens (~500 books)—
OpenAI logoGPT-6 Astra$10.00$50.001.1M tokens (~525 books)$200.00