Compare / Claude Fable 5.1 vs Phi 4

Claude Fable 5.1 vs Phi 4

Which is cheaper, which is more capable, and which does better at each kind of work, from 15 results on 3 sources that measured both models.

Claude Fable 5.1
Anthropic · profile
Phi 4
Microsoft · profile
Results compared
15
Shared sources
3

Claude Fable 5.1 or Phi 4? The short answer

  • Phi 4 is cheaper: $0.088 against $20.00 per million tokens, 229 times less.
  • Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index: 53.4 against 5.9.
  • Claude Fable 5.1 writes faster: 71 tokens a second against 42.
  • On our business benchmarks, Claude Fable 5.1 ranks higher for agents and tool use, reasoning and knowledge and writing.
  • On our business benchmarks, Phi 4 ranks higher for sticking to the facts.

At a glance

Claude Fable 5.1Phi 4
Price per million tokens$10.00 in · $50.00 out$0.070 in · $0.14 out
Blended (3 in : 1 out)$20.00$0.088
Cheapest host, blended$20.00 (Azure)–
Intelligence Index53.45.9
Spring Prompt overall65–
Output speed, tokens a second7142
Context window1,000,000 tokens16,384 tokens
WeightsClosedOpen
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 5.1Phi 4
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 161 122 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 195 178 of 195
WritingWhat people prefer in blind comparisons, and judged writing quality 15 of 187 175 of 187
Sticking to the factsSummarising without inventing things, and factual answers 4 of 153 3 of 153
Speed under pressureGood decisions against a real clock (fast chess) 22 of 22 not measured

Every shared result

BenchmarkMetricClaude Fable 5.1Phi 4
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4851,256
Arena (formerly LMArena)reportedCreative writingArena rating 1,4841,210
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5161,268
Arena (formerly LMArena)reportedInstruction followingArena rating 1,4971,245
Arena (formerly LMArena)reportedOverallArena rating 1,5011,256
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,4961,229
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 53.45.90
Artificial AnalysisreportedGPQA Diamond% of questions 93.7%57.5%
Artificial AnalysisreportedHumanity's Last Exam% of questions 59.1%3.8%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 85.3%0.0%
Artificial AnalysisreportedOutput speedtokens per second 70.642.3
Artificial AnalysisreportedTime to first answer tokenseconds 2.111.03
UGI LeaderboardreportedRequested-length error% off the requested word count 3.0%19.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.430.34
UGI LeaderboardreportedWriting scorescore out of 100 63.925.7

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 Phi 4?

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 and writing; Phi 4 ranks higher for sticking to the facts.

Which is cheaper, Claude Fable 5.1 or Phi 4?

Phi 4 costs $0.088 per million tokens (three input to one output), against $20.00 for Claude Fable 5.1.

Which is faster, Claude Fable 5.1 or Phi 4?

Claude Fable 5.1 writes about 71 tokens a second on its usual API, against 42 for Phi 4 (Artificial Analysis).

Run Claude Fable 5.1 and Phi 4 on your own prompt

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