Noometry

Model comparison

Claude Sonnet 5.5 vs Grok 3

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 39.9 on the Noometry Index.

Last verified . 15 shared benchmarks.

Claude Sonnet 5.5 Anthropic

61.9

Rank #10 Confirmed

Grok 3 xAI

39.9

Rank #157 Confirmed

Summary

  • They share 15 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 9 categories and Grok 3 in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 38.0.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 55.6% for Grok 3.

Side by side

Claude Sonnet 5.5Grok 3
ProviderAnthropicxAI
Noometry Index61.939.9
Released2026-09-282025-04-09
WeightsProprietaryProprietary
Context window1M—
Max output128K—
Input $ / M tokens$2—
Output $ / M tokens$10—
Results tracked3240

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Category by category

Coding Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 67.3 (#6), Grok 3: 41.9 (#115)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Coding15131432
FrontierCode52.1%—
Aider Polyglot—53.3%
CursorBench55.5%—
LMArena WebDev1774—
FrontierSWE61.9%—
SciCode61%—
WeirdML—37.2%
ALE-Bench1,819—

Agentic & Tool Use Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.0 (#16), Grok 3: 30.5 (#76)

BenchmarkClaude Sonnet 5.5Grok 3
APEX-Agents75.5%—
BALROG—29.5%

Reasoning Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 54.0 (#28), Grok 3: 13.7 (#333)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Hard Prompts14951434
Epoch Capabilities Index165.03138.33
ARC-AGI-2—0%
SimpleBench—36.1%
Kagi LLM Benchmark—61.3%
NYT Connections (extended)80.5%—
ARC-AGI-1—5.5%
CritPt31.4%—
Mystery Game Puzzles65%—

Math Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 87.9 (#6), Grok 3: 38.0 (#145)

BenchmarkClaude Sonnet 5.5Grok 3
OTIS Mock AIME 2024-2025100%55.6%
LMArena Math15101391
FrontierMath (Tiers 1-3)88.8%—
FrontierMath Tier 480.5%—
ProofBench100%—
Omni-MATH—46.4%
MATH Level 5—88.7%
FrontierMath (Feb 2025 set)—3.8%
FrontierMath Erdős2.9%—
FrontierMath Tier 4 (v1)—0%

Knowledge Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#12), Grok 3: 46.2 (#82)

BenchmarkClaude Sonnet 5.5Grok 3
GPQA Diamond95.6%75.8%
LMArena Expert15401421
SimpleQA Verified46.5%—
MMLU-Pro—78.8%
Confabulations—14.2%
Vectara Hallucination Rate—5.8%
GPQA (HELM)—65%

Multimodal Not comparable

Claude Sonnet 5.5: 51.5 (#6), Grok 3: —

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Vision1289—
Furniture Assembly75%—

Multilingual Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 55.3 (#30), Grok 3: 52.3 (#87)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Non-English14521410
LMArena Chinese15221448
LMArena Russian14511416
LMArena French—1460
LMArena German—1431
LMArena Japanese—1387
LMArena Korean—1373
LMArena Spanish—1417

Instruction Following Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 78.3 (#11), Grok 3: 75.0 (#73)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Instruction Following14951409
IFEval—88.4%

Long Context Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 45.9 (#28), Grok 3: 38.7 (#192)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Longer Query14981439
Fiction.LiveBench—58.3%

Writing & Preference Claude Sonnet 5.5 leads

Claude Sonnet 5.5: 66.0 (#40), Grok 3: 55.8 (#141)

BenchmarkClaude Sonnet 5.5Grok 3
LMArena Text14711426
LMArena Creative Writing14651414
LMArena Multi-Turn14741425
Short-Story Creative Writing—76.4%
EQ-Bench Creative Writing—1186
WildBench—84.9%

Frequently asked questions

Is Claude Sonnet 5.5 better than Grok 3?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 39.9 on the Noometry Index.

Is Claude Sonnet 5.5 or Grok 3 better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 41.9 in the Noometry coding category.

How many benchmarks do Claude Sonnet 5.5 and Grok 3 share?

15 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Grok 3 has 40.

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