Noometry

Model comparison

Claude Opus 5.5 vs Grok-3 mini

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 41.2 on the Noometry Index.

Last verified . 19 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

Grok-3 mini xAI

41.2

Rank #141 Confirmed

Summary

  • They share 19 benchmarks with published results for both. Claude Opus 5.5 scores higher in 8 categories and Grok-3 mini in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 13.6.
  • The biggest single-benchmark swing is ARC-AGI-2: 93.3% for Claude Opus 5.5 and 0.4% for Grok-3 mini.

Side by side

Claude Opus 5.5Grok-3 mini
ProviderAnthropicxAI
Noometry Index68.641.2
Released2026-09-222025-04-09
WeightsProprietaryProprietary
Context window1M—
Max output128K—
Input $ / M tokens$4—
Output $ / M tokens$20—
Results tracked4435

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.9 (#3), Grok-3 mini: 40.8 (#131)

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Coding15471379
FrontierCode54.6%—
Aider Polyglot—49.3%
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
SciCode66.9%—
WeirdML—42.6%
MirrorCode77.4%—
ALE-Bench2,147—

Agentic & Tool Use Not comparable

Claude Opus 5.5: 45.3 (#15), Grok-3 mini: —

BenchmarkClaude Opus 5.5Grok-3 mini
APEX-Agents73.5%—
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), Grok-3 mini: 13.6 (#334)

BenchmarkClaude Opus 5.5Grok-3 mini
ARC-AGI-293.3%0.4%
ARC-AGI-198.5%16.5%
LMArena Hard Prompts15351375
Epoch Capabilities Index167.33140.35
Kagi LLM Benchmark—61.3%
NYT Connections (extended)88.5%—
CritPt31.7%—
EBR-Bench71.4%—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Claude Opus 5.5 leads

Claude Opus 5.5: 91.8 (#3), Grok-3 mini: 42.1 (#85)

BenchmarkClaude Opus 5.5Grok-3 mini
OTIS Mock AIME 2024-2025100%77.8%
LMArena Math15061386
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
ProofBench100%—
Omni-MATH—31.8%
MATH Level 5—90.9%
FrontierMath (Feb 2025 set)—5.9%
FrontierMath Erdős2.9%—

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), Grok-3 mini: 46.4 (#81)

BenchmarkClaude Opus 5.5Grok-3 mini
GPQA Diamond90.6%76.3%
LMArena Expert15471395
SimpleQA Verified72.2%—
MMLU-Pro—79.9%
Confabulations—10.8%
GPQA (HELM)—67.5%

Multimodal Not comparable

Claude Opus 5.5: 57.8 (#1), Grok-3 mini: —

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Vision1321—
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), Grok-3 mini: 48.1 (#145)

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Non-English15071352
LMArena Chinese15881387
LMArena French15141357
LMArena Russian15201353
LMArena Spanish15071381
LMArena German—1349
LMArena Japanese—1342
LMArena Korean—1335

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), Grok-3 mini: 78.5 (#9)

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Instruction Following15371357
IFEval—95.1%

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.1 (#19), Grok-3 mini: 41.0 (#147)

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Longer Query15321372
Fiction.LiveBench—66.7%

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), Grok-3 mini: 52.5 (#169)

BenchmarkClaude Opus 5.5Grok-3 mini
LMArena Text15151370
LMArena Creative Writing15331342
LMArena Multi-Turn14991355
Short-Story Creative Writing—73.5%
EQ-Bench Creative Writing2050—
WildBench—65.1%

Frequently asked questions

Is Claude Opus 5.5 better than Grok-3 mini?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 41.2 on the Noometry Index.

Is Claude Opus 5.5 or Grok-3 mini better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 40.8 in the Noometry coding category.

How many benchmarks do Claude Opus 5.5 and Grok-3 mini share?

19 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Grok-3 mini has 35.

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