Model comparison

Claude Fable 5.1 vs Hy4 preview

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 45.3 on the Noometry Index. Hy4 preview costs 18× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 3 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Hy4 preview Tencent

45.3

Rank #73 Reported

Summary

  • They share 3 benchmarks with published results for both. Claude Fable 5.1 scores higher in 3 categories and Hy4 preview in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Fable 5.1 leads 76.7 to 31.9.
  • The biggest single-benchmark swing is ProofBench: 100% for Claude Fable 5.1 and 75% for Hy4 preview.
  • Hy4 preview is cheaper at $0.75 / $2.25 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Hy4 preview accepts more context: 1.05M tokens versus 1M.
  • Hy4 preview has downloadable open weights; the other is API-only.

Side by side

Claude Fable 5.1 and Hy4 preview specifications
Claude Fable 5.1Hy4 preview
ProviderAnthropicTencent
Noometry Index69.045.3
Released2026-09-012026-08-28
WeightsProprietaryOpen
Context window1M1.05M
Max output128K64K
Input $ / M tokens$10$0.75
Output $ / M tokens$50$2.25
Results tracked523

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), Hy4 preview: 51.6 (#38)

Coding benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena WebDev17441632
FrontierCode50.9%—
CursorBench51.8%—
FrontierSWE56.3%—
SciCode63.1%—
GSO88.2%—
WeirdML92.9%—
LMArena Coding1528—
MirrorCode73.3%—
ALE-Bench2,143—

Agentic & Tool Use Not comparable

Claude Fable 5.1: 50.7 (#5), Hy4 preview: —

Agentic & Tool Use benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
APEX-Agents68.6%—
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), Hy4 preview: 31.9 (#79)

Reasoning benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
NYT Connections (extended)90%68.2%
ARC-AGI-290%—
ARC-AGI-197.5%—
CritPt31.1%—
Chess Puzzles47%—
EBR-Bench57.1%—
LMArena Hard Prompts1526—
Mystery Game Puzzles58%—
DTBench97.6%—
LMCA65.5%—
Epoch Capabilities Index164.7—

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), Hy4 preview: 55.7 (#42)

Math benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
ProofBench100%75%
FrontierMath (Tiers 1-3)90.2%—
FrontierMath Tier 487.8%—
OTIS Mock AIME 2024-2025100%—
LMArena Math1525—
FrontierMath Erdős0%—

Knowledge Not comparable

Claude Fable 5.1: 69.6 (#6), Hy4 preview: —

Knowledge benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
Humanity's Last Exam46.5%—
SimpleQA Verified70.8%—
LMArena Expert1535—

Multimodal Not comparable

Claude Fable 5.1: 53.9 (#4), Hy4 preview: —

Multimodal benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena Vision1318—
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Not comparable

Claude Fable 5.1: 59.1 (#3), Hy4 preview: —

Multilingual benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena Non-English1507—
LMArena Chinese1586—
LMArena French1525—
LMArena German1500—
LMArena Japanese1543—
LMArena Korean1534—
LMArena Russian1521—
LMArena Spanish1516—

Instruction Following Not comparable

Claude Fable 5.1: 79.2 (#6), Hy4 preview: —

Instruction Following benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena Instruction Following1517—

Long Context Not comparable

Claude Fable 5.1: 46.7 (#20), Hy4 preview: —

Long Context benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena Longer Query1522—

Writing & Preference Not comparable

Claude Fable 5.1: 79.2 (#2), Hy4 preview: —

Writing & Preference benchmarks
BenchmarkClaude Fable 5.1Hy4 preview
LMArena Text1510—
LMArena Creative Writing1507—
EQ-Bench Creative Writing2162—
LMArena Multi-Turn1492—

Frequently asked questions

Is Claude Fable 5.1 better than Hy4 preview?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 45.3 on the Noometry Index. Hy4 preview costs 18× 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 Hy4 preview?

Hy4 preview is cheaper. It lists at $0.75 per million input tokens and $2.25 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or Hy4 preview better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 51.6 in the Noometry coding category.

Which has the bigger context window?

Hy4 preview does, with 1.05M tokens against 1M.

How many benchmarks do Claude Fable 5.1 and Hy4 preview share?

3 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Hy4 preview has 3.

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