Model comparison

Claude Fable 5.1 vs Grok 4 Heavy

Claude Fable 5.1 has enough public results to be ranked (#2); Grok 4 Heavy does not yet, so treat this comparison as directional.

Last verified . 0 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Grok 4 Heavy xAI

—

Unranked

Side by side

Claude Fable 5.1 and Grok 4 Heavy specifications
Claude Fable 5.1Grok 4 Heavy
ProviderAnthropicxAI
Noometry Index69.0—
Released2026-09-012025-07-10
WeightsProprietaryProprietary
Context window1M—
Max output128K—
Input $ / M tokens$10—
Output $ / M tokens$50—
Results tracked521

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Not comparable

Claude Fable 5.1: 74.7 (#1), Grok 4 Heavy: —

Coding benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
FrontierCode50.9%—
CursorBench51.8%—
LMArena WebDev1744—
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), Grok 4 Heavy: —

Agentic & Tool Use benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
APEX-Agents68.6%—
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Not comparable

Claude Fable 5.1: 76.7 (#7), Grok 4 Heavy: —

Reasoning benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
ARC-AGI-290%—
NYT Connections (extended)90%—
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 Not comparable

Claude Fable 5.1: 89.6 (#4), Grok 4 Heavy: —

Math benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
FrontierMath (Tiers 1-3)90.2%—
FrontierMath Tier 487.8%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math1525—
FrontierMath Erdős0%—
FrontierMath Tier 4 (v1)—2.1%

Knowledge Not comparable

Claude Fable 5.1: 69.6 (#6), Grok 4 Heavy: —

Knowledge benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
Humanity's Last Exam46.5%—
SimpleQA Verified70.8%—
LMArena Expert1535—

Multimodal Not comparable

Claude Fable 5.1: 53.9 (#4), Grok 4 Heavy: —

Multimodal benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
LMArena Vision1318—
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Not comparable

Claude Fable 5.1: 59.1 (#3), Grok 4 Heavy: —

Multilingual benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
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), Grok 4 Heavy: —

Instruction Following benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
LMArena Instruction Following1517—

Long Context Not comparable

Claude Fable 5.1: 46.7 (#20), Grok 4 Heavy: —

Long Context benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
LMArena Longer Query1522—

Writing & Preference Not comparable

Claude Fable 5.1: 79.2 (#2), Grok 4 Heavy: —

Writing & Preference benchmarks
BenchmarkClaude Fable 5.1Grok 4 Heavy
LMArena Text1510—
LMArena Creative Writing1507—
EQ-Bench Creative Writing2162—
LMArena Multi-Turn1492—

Frequently asked questions

Is Claude Fable 5.1 better than Grok 4 Heavy?

Claude Fable 5.1 has enough public results to be ranked (#2); Grok 4 Heavy does not yet, so treat this comparison as directional.

How many benchmarks do Claude Fable 5.1 and Grok 4 Heavy share?

0 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Grok 4 Heavy has 1.

Related comparisons

Go deeper