Model comparison

GPT-5 Pro vs Grok 4 Fast

GPT-5 Pro is the stronger model overall, scoring 46.2 to 39.0 on the Noometry Index.

Last verified . 5 shared benchmarks.

GPT-5 Pro OpenAI

46.2

Rank #58 Confirmed

Grok 4 Fast xAI

39.0

Rank #164 Confirmed

Summary

  • They share 5 benchmarks with published results for both. GPT-5 Pro scores higher in 4 categories and Grok 4 Fast in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GPT-5 Pro leads 56.2 to 31.5.
  • The biggest single-benchmark swing is ARC-AGI-1: 70.2% for GPT-5 Pro and 48.5% for Grok 4 Fast.

Side by side

GPT-5 Pro and Grok 4 Fast specifications
GPT-5 ProGrok 4 Fast
ProviderOpenAIxAI
Noometry Index46.239.0
Released2025-10-062025-09-19
WeightsProprietaryProprietary
Context window400K—
Max output272K—
Input $ / M tokens$15—
Output $ / M tokens$120—
Results tracked1230

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Category by category

Coding GPT-5 Pro leads

GPT-5 Pro: 43.4 (#77), Grok 4 Fast: 32.3 (#264)

Coding benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
WeirdML60.4%42.9%
LMArena WebDev—1160
LMArena Coding—1429
AlgoTune1.31—

Agentic & Tool Use Not comparable

GPT-5 Pro: —, Grok 4 Fast: 29.3 (#80)

Agentic & Tool Use benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
τ²-bench Banking—15.7%
Cybench—30%
LMArena Search—1171

Reasoning GPT-5 Pro leads

GPT-5 Pro: 39.2 (#52), Grok 4 Fast: 22.5 (#179)

Reasoning benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
ARC-AGI-218.3%5.3%
Kagi LLM Benchmark76.8%66.1%
ARC-AGI-170.2%48.5%
Epoch Capabilities Index150.26144.21
SimpleBench61.6%—
EnigmaEval18.8%—
LMArena Hard Prompts—1413
DTBench—82.7%
ForecastBench—60.5

Math GPT-5 Pro leads

GPT-5 Pro: 48.0 (#53), Grok 4 Fast: 36.1 (#126)

Math benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
FrontierMath (Tiers 1-3)55.8%—
FrontierMath Tier 419.5%—
LMArena Math—1419
FrontierMath Tier 4 (v1)14.6%—

Knowledge GPT-5 Pro leads

GPT-5 Pro: 56.2 (#39), Grok 4 Fast: 31.5 (#211)

Knowledge benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
Humanity's Last Exam31.6%—
Vectara Hallucination Rate—19.7%
LMArena Expert—1411

Multilingual Not comparable

GPT-5 Pro: —, Grok 4 Fast: 51.5 (#106)

Multilingual benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
LMArena Non-English—1397
LMArena Chinese—1458
LMArena French—1433
LMArena German—1383
LMArena Japanese—1358
LMArena Korean—1359
LMArena Russian—1387
LMArena Spanish—1414

Instruction Following Not comparable

GPT-5 Pro: —, Grok 4 Fast: 73.4 (#116)

Instruction Following benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
LMArena Instruction Following—1388

Long Context Not comparable

GPT-5 Pro: —, Grok 4 Fast: 63.2 (#3)

Long Context benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
Fiction.LiveBench—94.4%
LMArena Longer Query—1415

Writing & Preference Not comparable

GPT-5 Pro: —, Grok 4 Fast: 60.2 (#96)

Writing & Preference benchmarks
BenchmarkGPT-5 ProGrok 4 Fast
LMArena Text—1407
LMArena Creative Writing—1388
LMArena Multi-Turn—1414

Frequently asked questions

Is GPT-5 Pro better than Grok 4 Fast?

GPT-5 Pro is the stronger model overall, scoring 46.2 to 39.0 on the Noometry Index.

Is GPT-5 Pro or Grok 4 Fast better for coding?

GPT-5 Pro scores higher on coding benchmarks: 43.4 versus 32.3 in the Noometry coding category.

How many benchmarks do GPT-5 Pro and Grok 4 Fast share?

5 benchmarks have published results for both models. GPT-5 Pro has 12 scored results on Noometry and Grok 4 Fast has 30.

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