Comparing 2 models

Claude Fable 5.1 vs DeepSeek V4.1 Flash

Benchmarks through

Verdict

Claude Fable 5.1 places higher on 5 of the 5 tasks where both are ranked. DeepSeek V4.1 Flash costs 277.8x less per input token. DeepSeek V4.1 Flash accepts 1.0x more context. Only DeepSeek V4.1 Flash has open weights for self-hosting.

  • Choose Claude Fable 5.1 for Agentic Coding (#2), AI Agents (#2), Debugging & Code Review (#3).
  • Choose DeepSeek V4.1 Flash for you need to self-host.

Built from the published task rankings below; ranks come from each task's own weighted benchmarks, so a win on one task says nothing about another.

metric
Model 1Claude Fable 5.1
Model 2DeepSeek V4.1 Flash
Best for
Competition Math (#1)
Best Cheap LLM for High Volume (#1)
Provider
anthropic
deepseek
Context
1M
1.0MBest
Input / 1M
$10
$0.036Best
Output / 1M
$50
$0.68Best
Tool use
yesBest
yesBest
Vision
yesBest
yesBest
Reasoning
yesBest
yesBest
Open-weight
—
yesBest
Released
Aug 29, 2026
Sep 10, 2026

Measured head to head

Benchmarks both models were run on

EvaluationClaude Fable 5.1DeepSeek V4.1 FlashSource
FrontierMath Tiers 1-3 (Epoch AI)90.2% ± 1.867.4% ± 2.8source · 2026-09-01
LiveBench Agentic Coding66.1%77.3%source · 2026-10-16
LiveBench Coding86.4%80.0%source · 2026-10-16
LiveBench Data Analysis80.3%79.3%source · 2026-10-16
LiveBench Instruction Following73.0%70.0%source · 2026-10-16
LiveBench Language89.5%81.2%source · 2026-10-16
LiveBench Math97.0%93.3%source · 2026-10-16
LiveBench Reasoning91.7%86.7%source · 2026-10-16
LMArena Agent14.13source · 2026-10-14
LMArena Agent Bash Recovery11.67.9source · 2026-10-08
LMArena Agent Steerability14.71.9source · 2026-10-14
LMArena Agent Task Outcome15.77.5source · 2026-10-14
LMArena Agent Tool Hallucination0.60.5source · 2026-10-14
LMArena Creative Writing1508 Elo1437 Elosource · 2026-10-15
LMArena Instruction Following1517 Elo1473 Elosource · 2026-10-15
LMArena Long Query1523 Elo1474 Elosource · 2026-10-15
LMArena Math1528 Elo1478 Elosource · 2026-10-15
LMArena Text1502 Elo1475 Elosource · 2026-10-15
LMArena Text Factuality1498 Elo1468 Elosource · 2026-10-15
LMArena Vision1286 Elo1260 Elosource · 2026-10-09
LMArena Vision Diagrams1326 Elo1291 Elosource · 2026-10-09
LMArena Vision OCR1302 Elo1270 Elosource · 2026-10-09
LMArena WebDev1743 Elo1619 Elosource · 2026-10-13
LMArena WebDev Image-to-Web1720 Elo1609 Elosource · 2026-10-09
OTIS Mock AIME (Epoch AI)100% ± 098.3% ± 0.6source · 2026-09-01
SimpleQA Verified (Epoch AI)70.8% ± 1.442.9% ± 1.6source · 2026-09-01

Values are as published by each evaluator, in its own units; rows from different evaluators are not on a common scale.

task evidence

How they place when the question changes

Lower ranks are better. “Best” marks the strongest option in this shortlist for that task.