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Claude Fable 5 vs GPT-4.1 Nano

Head to head on 11 shared benchmarks, with price, context window, and release dates.

Benchmark scores

62

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Model
Claude Fable 5

Anthropic

71.8%1933elo8392.6%55.5%63.5%68.9%60.2%76.9%62.9%98.5%----17.4%-83.9%-38.6%---90.0%1340elo78.0%56.3%29.3%--29.8%1932elo-66.0%-13.3%81.4%78.6%80.0%59.9%88.5%93.9%87.3%---56.1%88.5%-85.0%95.0%51.9%-80.3%88.0%--66.0%74.2%90.4%--69.4%
GPT-4.1 Nano

OpenAI

42.1%944elo32.451.2%3.8%32.0%52.8%25.9%60.8%3.8%17.3%8.9%23.7%24.0%10.7%-1.53--0.17-3.3%0.0%42.5%-----1.0%0.39--1.46-0.0%--------32.6%10.8%84.8%--65.7%---0.44--1.6439.8%---68.0%68.0%30.9%
2 / 2 models
AttributeClaude Fable 5

Anthropic

GPT-4.1 Nano

OpenAI

DescriptionClaude Fable 5 is Anthropic's most capable widely released model, built for the most demanding reasoning and long-horizon agentic work. Shares its base model with the invitation-only Claude Mythos 5.GPT-4.1 Nano is an AI model from OpenAI.
FamilyClaudeGPT
Params--
Open weightsclosedclosed
License-proprietary
Released9 Jun 202614 Apr 2025
Context1,000,0001,047,576
Input $/1M$10.00$0.10
Output $/1M$50.00$0.40
Cache read $/1M$1.000$0.025
Cache write $/1M$12.500-
Speed66 tok/s0 tok/s
Latency49.62 s0.00 s
Modalitiestext, image, fileimage, text, file
Providers--
PublisherAnthropicOpenAI
Reported scores
IFBench63.5% (AA)
LiveBench - Math93.9% (LiveBench)
LiveBench - Coding78.6% (LiveBench)

FAQ

Is Claude Fable 5 or GPT-4.1 Nano better?
Across the 11 benchmarks both models report on Sophon, Claude Fable 5 leads on 11 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do Claude Fable 5 and GPT-4.1 Nano compare on GPQA Diamond?
Claude Fable 5 scores 92.6% and GPT-4.1 Nano scores 51.2% on GPQA Diamond.
Which is cheaper, Claude Fable 5 or GPT-4.1 Nano?
GPT-4.1 Nano is cheaper at $0.40 per million output tokens against $50.00 for Claude Fable 5 - about 125.0x.
When were Claude Fable 5 and GPT-4.1 Nano released?
Claude Fable 5 was released 9 Jun 2026 by Anthropic. GPT-4.1 Nano was released 14 Apr 2025 by OpenAI.

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