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Claude Fable 5 vs Claude Opus 4.5

Head to head on 23 shared benchmarks, with price, context window, and release dates.

Benchmark scores

58

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Model
Claude Fable 5

Anthropic

71.8%1933elo8392.6%55.5%63.5%81.4%78.6%80.0%59.9%88.5%93.9%87.3%56.1%88.5%68.9%95.0%51.9%60.2%76.9%62.9%90.4%98.5%-17.4%83.9%38.6%-90.0%--1340elo78.0%56.3%29.3%-29.8%1932elo--66.0%--13.3%----85.0%----80.3%-88.0%66.0%74.2%69.4%
Claude Opus 4.5

Anthropic

61.3%1683elo73.181.0%13.2%43.0%78.1%79.7%74.4%62.5%81.3%90.4%80.1%45.2%83.2%68.7%36.0%45.0%47.0%74.3%40.9%20.6%86.3%62.7%---16.7%-35.6%6.1%----20.7%--84.7%12.13-83.8%83.5%-73.8%88.9%100.0%37.4-77.5%45.370.7%79.2%-61.8---62.2%
2 / 2 models
AttributeClaude Fable 5

Anthropic

Claude Opus 4.5

Anthropic

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.Claude Opus 4.5 is an AI model from Anthropic.
FamilyClaudeClaude
Params--
Open weightsclosedclosed
License-proprietary
Released9 Jun 202624 Nov 2025
Context1,000,000200,000
Input $/1M$10.00$5.00
Output $/1M$50.00$25.00
Cache read $/1M$1.000$0.500
Cache write $/1M$12.500$6.250
Speed66 tok/s0 tok/s
Latency49.62 s0.00 s
Modalitiestext, image, filefile, image, text
Providers--
PublisherAnthropicAnthropic
Reported scores
IFBench63.5% (AA)
LiveBench - Math93.9% (LiveBench)
LiveBench - Coding78.6% (LiveBench)

FAQ

Is Claude Fable 5 or Claude Opus 4.5 better?
Across the 23 benchmarks both models report on Sophon, Claude Fable 5 leads on 21 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do Claude Fable 5 and Claude Opus 4.5 compare on GPQA Diamond?
Claude Fable 5 scores 92.6% and Claude Opus 4.5 scores 81.0% on GPQA Diamond.
Which is cheaper, Claude Fable 5 or Claude Opus 4.5?
Claude Opus 4.5 is cheaper at $25.00 per million output tokens against $50.00 for Claude Fable 5 - about 2.0x.
When were Claude Fable 5 and Claude Opus 4.5 released?
Claude Fable 5 was released 9 Jun 2026 by Anthropic. Claude Opus 4.5 was released 24 Nov 2025 by Anthropic.

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