Noometry

Model comparison

Claude Fable 5.1 vs Qwen3 8B

Claude Fable 5.1 is the stronger model overall, scoring 68.5 to 33.3 on the Noometry Index. Qwen3 8B costs 65× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 7 shared benchmarks.

Claude Fable 5.1 Anthropic

68.5

Rank #2 Confirmed

Qwen3 8B Alibaba (Qwen)

33.3

Rank #237 Confirmed

Summary

  • They share 7 benchmarks with published results for both. Claude Fable 5.1 scores higher in 6 categories and Qwen3 8B in 0 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Fable 5.1 leads 76.7 to 16.1.
  • The biggest single-benchmark swing is LMCA: 65.5% for Claude Fable 5.1 and 8.8% for Qwen3 8B.
  • Qwen3 8B is cheaper at $0.18 / $0.70 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Claude Fable 5.1 accepts more context: 1M tokens versus 131K.
  • Qwen3 8B has downloadable open weights; the other is API-only.

Side by side

Claude Fable 5.1Qwen3 8B
ProviderAnthropicAlibaba (Qwen)
Noometry Index68.533.3
Released2026-09-012025-04
WeightsProprietaryOpen
Context window1M131K
Max output128K8K
Input $ / M tokens$10$0.18
Output $ / M tokens$50$0.70
Results tracked5011

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 70.5 (#2), Qwen3 8B: 33.4 (#245)

BenchmarkClaude Fable 5.1Qwen3 8B
SciCode63.1%22.6%
FrontierCode50.9%—
CursorBench51.8%—
LMArena WebDev1753—
FrontierSWE56.3%—
WeirdML92.9%—
LMArena Coding1523—
MirrorCode73.3%—
ALE-Bench2,143—

Agentic & Tool Use Claude Fable 5.1 leads

Claude Fable 5.1: 50.8 (#5), Qwen3 8B: 29.9 (#71)

BenchmarkClaude Fable 5.1Qwen3 8B
APEX-Agents68.6%—
Berkeley Function Calling Leaderboard—42.6%
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#5), Qwen3 8B: 16.1 (#299)

BenchmarkClaude Fable 5.1Qwen3 8B
CritPt31.1%0%
Chess Puzzles47%5%
DTBench97.6%59.7%
LMCA65.5%8.8%
Epoch Capabilities Index165136.17
ARC-AGI-290%—
NYT Connections (extended)90%—
ARC-AGI-197.5%—
EBR-Bench57.1%—
LMArena Hard Prompts1526—
Mystery Game Puzzles58%—

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.5 (#3), Qwen3 8B: 33.3 (#176)

BenchmarkClaude Fable 5.1Qwen3 8B
OTIS Mock AIME 2024-2025100%56.1%
FrontierMath (Tiers 1-3)90.2%—
FrontierMath Tier 487.8%—
ProofBench100%—
LMArena Math1519—
FrontierMath Erdős0%—

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.3 (#5), Qwen3 8B: 36.1 (#164)

BenchmarkClaude Fable 5.1Qwen3 8B
GPQA Diamond—56.8%
Humanity's Last Exam46.5%—
SimpleQA Verified70.8%—
Vectara Hallucination Rate—4.8%
LMArena Expert1528—

Multimodal Not comparable

Claude Fable 5.1: 54.1 (#4), Qwen3 8B: —

BenchmarkClaude Fable 5.1Qwen3 8B
LMArena Vision1319—
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Not comparable

Claude Fable 5.1: 59.5 (#2), Qwen3 8B: —

BenchmarkClaude Fable 5.1Qwen3 8B
LMArena Non-English1509—
LMArena Chinese1589—
LMArena French1532—
LMArena German1495—
LMArena Japanese1565—
LMArena Russian1525—
LMArena Spanish1503—

Instruction Following Not comparable

Claude Fable 5.1: 79.3 (#6), Qwen3 8B: —

BenchmarkClaude Fable 5.1Qwen3 8B
LMArena Instruction Following1515—

Long Context Claude Fable 5.1 leads

Claude Fable 5.1: 46.8 (#19), Qwen3 8B: 37.8 (#205)

BenchmarkClaude Fable 5.1Qwen3 8B
Fiction.LiveBench—62.1%
LMArena Longer Query1524—

Writing & Preference Not comparable

Claude Fable 5.1: 79.3 (#1), Qwen3 8B: —

BenchmarkClaude Fable 5.1Qwen3 8B
LMArena Text1511—
LMArena Creative Writing1507—
EQ-Bench Creative Writing2162—
LMArena Multi-Turn1492—

Frequently asked questions

Is Claude Fable 5.1 better than Qwen3 8B?

Claude Fable 5.1 is the stronger model overall, scoring 68.5 to 33.3 on the Noometry Index. Qwen3 8B costs 65× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Which is cheaper, Claude Fable 5.1 or Qwen3 8B?

Qwen3 8B is cheaper. It lists at $0.18 per million input tokens and $0.70 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or Qwen3 8B better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 70.5 versus 33.4 in the Noometry coding category.

Which has the bigger context window?

Claude Fable 5.1 does, with 1M tokens against 131K.

How many benchmarks do Claude Fable 5.1 and Qwen3 8B share?

7 benchmarks have published results for both models. Claude Fable 5.1 has 50 scored results on Noometry and Qwen3 8B has 11.

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