Compare / Claude Fable 5.1 vs GPT-4.1 Nano

Claude Fable 5.1 vs GPT-4.1 Nano

Which is cheaper, which is more capable, and which does better at each kind of work, from 14 results on 3 sources that measured both models.

Claude Fable 5.1
Anthropic · profile
GPT-4.1 Nano
OpenAI · profile
Results compared
14
Shared sources
3

Claude Fable 5.1 or GPT-4.1 Nano? The short answer

  • GPT-4.1 Nano is cheaper: $0.18 against $20.00 per million tokens, 114 times less.
  • Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index: 53.4 against 7.8.
  • On our business benchmarks, Claude Fable 5.1 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.

At a glance

Claude Fable 5.1GPT-4.1 Nano
Price per million tokens$10.00 in · $50.00 out$0.10 in · $0.40 out
Blended (3 in : 1 out)$20.00$0.18
Cheapest host, blended$20.00 (Azure)$0.18 (Azure)
Intelligence Index53.47.8
Spring Prompt overall65–
Output speed, tokens a second71–
Context window1,000,000 tokens1,047,576 tokens
WeightsClosedClosed
Developer based inthe USthe US

Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.

Which is better for what

Each model's rank among models available today, for each kind of work, from our own benchmarks and licensed sources. The better rank is in green.

Use caseClaude Fable 5.1GPT-4.1 Nano
Product listingsTurning a sparse product feed and photos into listings that can go live 14 of 19 not measured
Decks from an analysisTurning a finished analysis into a deck you could present as it is 6 of 18 not measured
Marketing planningPlanning a year of ad spend without overspending 6 of 18 not measured
Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls 14 of 161 139 of 161
Professional workReal tasks from banking, consulting and law, business documents and freelance projects 4 of 51 not measured
Reasoning and knowledgeHard questions across science, maths and general knowledge 4 of 195 169 of 195
WritingWhat people prefer in blind comparisons, and judged writing quality 15 of 187 162 of 187
Sticking to the factsSummarising without inventing things, and factual answers 4 of 153 151 of 153
Speed under pressureGood decisions against a real clock (fast chess) 22 of 22 not measured

Every shared result

BenchmarkMetricClaude Fable 5.1GPT-4.1 Nano
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4851,321
Arena (formerly LMArena)reportedCreative writingArena rating 1,4841,307
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5161,313
Arena (formerly LMArena)reportedInstruction followingArena rating 1,4971,300
Arena (formerly LMArena)reportedOverallArena rating 1,5011,322
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,4961,299
Artificial AnalysisreportedArtificial Analysis Coding Indexindex score 81.611.1
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 53.47.80
Artificial AnalysisreportedGPQA Diamond% of questions 93.7%51.2%
Artificial AnalysisreportedHumanity's Last Exam% of questions 59.1%3.8%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 85.3%20.3%
Artificial AnalysisreportedTerminal-Bench 2.1% of tasks 91.4%3.7%
Artificial AnalysisreportedΤ-bench banking% of tasks 47.2%3.5%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 70.8%6.0%

Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.

Quick answers

Is Claude Fable 5.1 better than GPT-4.1 Nano?

It depends on the task. Among models available today, on our benchmarks and licensed sources, Claude Fable 5.1 ranks higher for agents and tool use, reasoning and knowledge, writing and sticking to the facts.

Which is cheaper, Claude Fable 5.1 or GPT-4.1 Nano?

GPT-4.1 Nano costs $0.18 per million tokens (three input to one output), against $20.00 for Claude Fable 5.1.

Run Claude Fable 5.1 and GPT-4.1 Nano on your own prompt

Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.