Compare · ModelsLive · 2 picked · head to head
Claude Fable 5.1 vs Claude Sonnet 5.5
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
Claude Fable 5.1 wins on 10/19 benchmarks
Claude Fable 5.1 wins 10 of 19 shared benchmarks. Leads in knowledge · math.
Category leads
speed·Claude Sonnet 5.5agentic·Claude Sonnet 5.5knowledge·Claude Fable 5.1coding·Claude Sonnet 5.5math·Claude Fable 5.1general·Claude Sonnet 5.5
Hype vs Reality
Attention vs performance
Claude Fable 5.1
#24 by perf·#11 by attention
Claude Sonnet 5.5
#34 by perf·#12 by attention
Best value
Claude Sonnet 5.5
4.8x better value than Claude Fable 5.1
Claude Fable 5.1
2.3 pts/$
$30.00/M
Claude Sonnet 5.5
11.0 pts/$
$6.00/M
Vendor risk
Who is behind the model
Anthropic
$965.0B·Tier 1
Anthropic
$965.0B·Tier 1
Head to head
19 benchmarks · 2 models
Claude Fable 5.1Claude Sonnet 5.5
Artificial Analysis · CritPt
Claude Sonnet 5.5 leads by +1.7
Claude Fable 5.1
29.7
Claude Sonnet 5.5
31.4
Artificial Analysis · GDPval
Claude Sonnet 5.5 leads by +4.2
Claude Fable 5.1
62.7
Claude Sonnet 5.5
66.9
Artificial Analysis · Humanity's Last Exam
Claude Fable 5.1 leads by +4.1
Claude Fable 5.1
59.1
Claude Sonnet 5.5
55.0
Artificial Analysis · Long Context Reasoning
Claude Fable 5.1 leads by +2.6
Claude Fable 5.1
85.3
Claude Sonnet 5.5
82.7
Artificial Analysis · Quality Index
Claude Sonnet 5.5 leads by +2.6
Claude Fable 5.1
53.4
Claude Sonnet 5.5
56.0
Artificial Analysis · SciCode
Claude Fable 5.1 leads by +2.1
Claude Fable 5.1
63.1
Claude Sonnet 5.5
61.0
APEX-Agents
Claude Sonnet 5.5 leads by +6.9
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
Claude Sonnet 5.5
75.5
Chess Puzzles
Claude Sonnet 5.5 leads by +11.6
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
Claude Fable 5.1
45.3
Claude Sonnet 5.5
56.9
Frontiercode
Claude Sonnet 5.5 leads by +1.2
Claude Fable 5.1
50.9
Claude Sonnet 5.5
52.1
FrontierMath-Tier-4-v2-Private
Claude Fable 5.1 leads by +7.3
Claude Fable 5.1
87.8
Claude Sonnet 5.5
80.5
FrontierMath-Tiers-1-3-v2-Private
Claude Fable 5.1 leads by +1.4
Claude Fable 5.1
90.2
Claude Sonnet 5.5
88.8
Frontierswe
Claude Sonnet 5.5 leads by +5.6
Claude Fable 5.1
56.3
Claude Sonnet 5.5
61.9
Furniture Assembly
Claude Sonnet 5.5 leads by +7.2
Claude Fable 5.1
57.1
Claude Sonnet 5.5
64.3
HLE
Claude Fable 5.1 leads by +0.4
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 Sonnet 5.5
43.4
Mystery Game Puzzles
Claude Sonnet 5.5 leads by +7.7
Claude Fable 5.1
53.7
Claude Sonnet 5.5
61.5
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
Claude Sonnet 5.5
100.0
Proofbench
Claude Fable 5.1
100.0
Claude Sonnet 5.5
100.0
SimpleQA Verified
Claude Fable 5.1 leads by +24.3
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
Claude Sonnet 5.5
46.5
SpireClimb
Claude Fable 5.1 leads by +0.7
Claude Fable 5.1
2.0
Claude Sonnet 5.5
1.3
Full benchmark table
| Benchmark | Claude Fable 5.1 | Claude Sonnet 5.5 |
|---|---|---|
Artificial Analysis · CritPt | 29.7 | 31.4 |
Artificial Analysis · GDPval | 62.7 | 66.9 |
Artificial Analysis · Humanity's Last Exam | 59.1 | 55.0 |
Artificial Analysis · Long Context Reasoning | 85.3 | 82.7 |
Artificial Analysis · Quality Index | 53.4 | 56.0 |
Artificial Analysis · SciCode | 63.1 | 61.0 |
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 | 75.5 |
Chess Puzzles Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities. | 45.3 | 56.9 |
Frontiercode | 50.9 | 52.1 |
FrontierMath-Tier-4-v2-Private | 87.8 | 80.5 |
FrontierMath-Tiers-1-3-v2-Private | 90.2 | 88.8 |
Frontierswe | 56.3 | 61.9 |
Furniture Assembly | 57.1 | 64.3 |
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%. | 43.8 | 43.4 |
Mystery Game Puzzles | 53.7 | 61.5 |
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 | 100.0 |
SimpleQA Verified SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information. | 70.8 | 46.5 |
SpireClimb | 2.0 | 1.3 |
Pricing · per 1M tokens · projected $/mo at 10M tokens
| Model | Input | Output | Context | Projected $/mo |
|---|---|---|---|---|
| $10.00 | $50.00 | 1.0M tokens (~500 books) | $200.00 | |
| $2.00 | $10.00 | 1.0M tokens (~500 books) | $40.00 |