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Claude Fable 5.2 vs Fugu Ultra v2

Compare canonical objects directly. The useful dimensions change with the object type, so model and hardware comparisons stay separate.

ModelsHardware
Claude Fable 5.2

Anthropic

Sources:models.devOpenRouter

Fugu Ultra v2

Sakana AI

Sources:models.devOpenRouter

Benchmark results

  • Arena WebDev

    Arena rating · Higher is better

    • Claude Fable 5.2
      1836
      Arena #1CI 1813 to 1858
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • xhigh183695% CI 1813 to 1858 · 994 votes
    Fugu Ultra v2

    Not reported

    Source:Arena WebDev leaderboard, 2026-11-10

  • Agent Arena

    IPS score · Higher is better

    • Claude Fable 5.2
      +0.304
      Arena #1CI +0.264 to +0.343
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max+0.30495% CI +0.264 to +0.343 · 577,927 observations
    Fugu Ultra v2

    Not reported

    Source:Agent Arena leaderboard, 2026-11-11

  • ARC-AGI-2

    Best published score · Higher is better

    • Claude Fable 5.2
      93.8%
      #4 of 85
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • low86.7%
    • medium89.6%
    • high90.4%
    • xhigh93.8%
    • max92.5%
    Fugu Ultra v2

    Not reported

    Source:External evaluation via Epoch AIOriginal-source terms apply

  • FrontierMath-Tier-4-v2-Private

    Best published score · Higher is better

    • Claude Fable 5.2
      100.0%
      #1 of 72
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max100.0%
    Fugu Ultra v2

    Not reported

    Source:Epoch AI evaluation

  • FrontierMath-Tiers-1-3-v2-Private

    Best published score · Higher is better

    • Claude Fable 5.2
      95.1%
      #1 of 87
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max95.1%
    Fugu Ultra v2

    Not reported

    Source:Epoch AI evaluation

  • GPQA diamond

    Best published score · Higher is better

    • Claude Fable 5.2
      93.9%
      #14 of 161
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max93.9%
    Fugu Ultra v2

    Not reported

    Source:Epoch AI evaluation

  • OTIS Mock AIME 2024-2025

    Best published score · Higher is better

    • Claude Fable 5.2
      99.7%
      #13 of 158
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max99.7%
    Fugu Ultra v2

    Not reported

    Source:Epoch AI evaluation

  • SimpleQA Verified

    Best published score · Higher is better

    • Claude Fable 5.2
      94.0%
      #1 of 87
    • Fugu Ultra v2
      Not reported
    Runs and sources
    Claude Fable 5.2
    • max94.0%
    Fugu Ultra v2

    Not reported

    Source:Epoch AI evaluation

Each model's best published result is shown; "Not reported" means no matched evaluation, not a score of zero. Arena and DeepSWE ranks are the leaderboards' own; other ranks are among catalogue models with a score. Results from different harnesses or settings are not directly comparable.

Original-source terms apply to evaluations credited to their original publishers.

Benchmark compilation: Epoch AI, Capabilities & benchmarking (CC BY attribution). Scores are converted to percentages and model names matched to the Vertical Tabs catalog. Individual evaluations are credited to their original sources. External results may carry separate licences and evaluation configurations; do not interpret scores from different harnesses as directly comparable.

Arena ratings: Arena (lmarena-ai/leaderboard-dataset), licensed CC BY 4.0. Ratings come from pairwise human votes and are only comparable within one leaderboard; the interval is Arena's 95% confidence interval. Model names are matched to the Vertical Tabs catalog.

Model specifications

Release date
November 7, 2026
September 11, 2026
Context window
1M
1M
Native context
—
—
Max output tokens
128,000
128,000
Knowledge cutoff
2026-06
2026-08-28
Open weights
Closed
Closed
Parameter count
—
—

API pricing · USD per 1M tokens

Input
$8.00
$5.00
Output
$40.00
$30.00
Cached input
$0.20
$0.50
Cache write
$10.00
—

Capabilities and modalities

Input modalities
text, image, file
text, image, file
Output modalities
text
text
Tool calling
Supported
Supported
Reasoning option
Supported
Supported
Supported options
include_reasoning, max_completion_tokens, max_tokens, reasoning, reasoning_effort, response_format, stop, structured_outputs, tool_choice, tools, verbosity
include_reasoning, reasoning, reasoning_effort, structured_outputs, tool_choice, tools, web_search_options
Capabilities
—
—

Architecture and availability

Architecture
—
—
Model families
—
—
Tokenizer
Claude
Other
Instruction format
—
—
License
—
—
Providers
4
1
Provider endpoints
10
1
Ollama variants
0
0
Metadata source
ai-research
ai-research

A dash means the field is not reported. Provider-specific performance and pricing may differ.

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