Model comparison

GPT-5.5 vs Grok 3

GPT-5.5 is the stronger model overall, scoring 63.4 to 39.9 on the Noometry Index.

Last verified . 29 shared benchmarks.

GPT-5.5 OpenAI

63.4

Rank #9 Confirmed

Grok 3 xAI

39.9

Rank #157 Confirmed

Summary

  • They share 29 benchmarks with published results for both. GPT-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 reasoning, where GPT-5.5 leads 72.8 to 13.7.
  • The biggest single-benchmark swing is ARC-AGI-1: 95% for GPT-5.5 and 5.5% for Grok 3.

Side by side

GPT-5.5 and Grok 3 specifications
GPT-5.5Grok 3
ProviderOpenAIxAI
Noometry Index63.439.9
Released2026-04-232025-04-09
WeightsProprietaryProprietary
Context window1.05M—
Max output128K—
Input $ / M tokens$5—
Output $ / M tokens$30—
Results tracked7140

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Category by category

Coding GPT-5.5 leads

GPT-5.5: 58.2 (#17), Grok 3: 41.9 (#115)

Coding benchmarks
BenchmarkGPT-5.5Grok 3
WeirdML84.9%37.2%
LMArena Coding14941432
SWE-bench Verified80.6%—
DeepSWE67%—
FrontierCode43%—
Aider Polyglot—53.3%
LMArena WebDev1513—
SciCode56.1%—
GSO40.2%—
MirrorCode10%—
ALE-Bench1,943—

Agentic & Tool Use GPT-5.5 leads

GPT-5.5: 50.7 (#6), Grok 3: 30.5 (#76)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.5Grok 3
Terminal-Bench84.7%—
APEX-Agents55.1%—
OSWorld 2.013%—
Remote Labor Index6.3%—
τ²-bench Banking44.6%—
DeepResearch Bench54%—
PostTrainBench27.2%—
BALROG—29.5%
ExploitBench47.4%—
GBAEval53.2%—
GDP.pdf26%—
LMArena Search1242—
Vending-Bench 27,524—

Reasoning GPT-5.5 leads

GPT-5.5: 72.8 (#11), Grok 3: 13.7 (#333)

Reasoning benchmarks
BenchmarkGPT-5.5Grok 3
ARC-AGI-285%0%
SimpleBench69%36.1%
Kagi LLM Benchmark88.8%61.3%
ARC-AGI-195%5.5%
LMArena Hard Prompts14891434
Epoch Capabilities Index159.1138.33
NYT Connections (extended)96.2%—
CritPt27.1%—
Chess Puzzles54%—
EBR-Bench34.3%—
Mystery Game Puzzles56%—
DTBench96%—
LMCA54.3%—
Surface Evolver Bench88.1%—
Bench to the Future 30.14—
ForecastBench60.6—

Math GPT-5.5 leads

GPT-5.5: 81.7 (#11), Grok 3: 38.0 (#145)

Knowledge GPT-5.5 leads

GPT-5.5: 64.4 (#17), Grok 3: 46.2 (#82)

Knowledge benchmarks
BenchmarkGPT-5.5Grok 3
GPQA Diamond94%75.8%
Vectara Hallucination Rate9.3%5.8%
LMArena Expert15081421
SimpleQA Verified63%—
MMLU-Pro—78.8%
Confabulations—14.2%
GPQA (HELM)—65%

Multimodal Not comparable

GPT-5.5: 46.9 (#12), Grok 3: —

Multimodal benchmarks
BenchmarkGPT-5.5Grok 3
LMArena Vision1297—
Blueprint-Bench 236.2%—
Furniture Assembly44.2%—
LMArena Document1486—

Multilingual GPT-5.5 leads

GPT-5.5: 56.4 (#20), Grok 3: 52.3 (#87)

Multilingual benchmarks
BenchmarkGPT-5.5Grok 3
LMArena Non-English14671410
LMArena Chinese15331448
LMArena French14861460
LMArena German14801431
LMArena Japanese14981387
LMArena Korean14601373
LMArena Russian14731416
LMArena Spanish14681417

Instruction Following GPT-5.5 leads

GPT-5.5: 77.5 (#18), Grok 3: 75.0 (#73)

Instruction Following benchmarks
BenchmarkGPT-5.5Grok 3
LMArena Instruction Following14791409
IFEval—88.4%

Long Context GPT-5.5 leads

GPT-5.5: 48.3 (#12), Grok 3: 38.7 (#192)

Long Context benchmarks
BenchmarkGPT-5.5Grok 3
LMArena Longer Query14841439
Fiction.LiveBench—58.3%
CL-bench Life22.2%—

Writing & Preference GPT-5.5 leads

GPT-5.5: 72.7 (#13), Grok 3: 55.8 (#141)

Writing & Preference benchmarks
BenchmarkGPT-5.5Grok 3
LMArena Text14721426
LMArena Creative Writing14551414
EQ-Bench Creative Writing18441186
LMArena Multi-Turn14761425
Short-Story Creative Writing—76.4%
WildBench—84.9%
EQ-Bench 41315—

Frequently asked questions

Is GPT-5.5 better than Grok 3?

GPT-5.5 is the stronger model overall, scoring 63.4 to 39.9 on the Noometry Index.

Is GPT-5.5 or Grok 3 better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.2 versus 41.9 in the Noometry coding category.

How many benchmarks do GPT-5.5 and Grok 3 share?

29 benchmarks have published results for both models. GPT-5.5 has 71 scored results on Noometry and Grok 3 has 40.

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