Model comparison

GPT-5 vs Grok 4.5

Grok 4.5 is the stronger model overall, scoring 55.0 to 50.9 on the Noometry Index.

Last verified . 39 shared benchmarks.

GPT-5 OpenAI

50.9

Rank #45 Confirmed

Grok 4.5 xAI

55.0

Rank #25 Confirmed

Summary

  • They share 39 benchmarks with published results for both. GPT-5 scores higher in 2 categories and Grok 4.5 in 8 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in long context, where GPT-5 leads 69.5 to 44.8.
  • The biggest single-benchmark swing is ARC-AGI-2: 9.9% for GPT-5 and 52.6% for Grok 4.5.
  • Grok 4.5 is cheaper at $2 / $6 per million input/output tokens, against $1.25 / $10 for GPT-5.
  • Grok 4.5 accepts more context: 500K tokens versus 400K.

Side by side

GPT-5 and Grok 4.5 specifications
GPT-5Grok 4.5
ProviderOpenAIxAI
Noometry Index50.955.0
Released2025-08-072026-07-08
WeightsProprietaryProprietary
Context window400K500K
Max output128K500K
Input $ / M tokens$1.25$2
Output $ / M tokens$10$6
Results tracked6952

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Category by category

Coding Grok 4.5 leads

GPT-5: 50.3 (#47), Grok 4.5: 52.2 (#35)

Coding benchmarks
BenchmarkGPT-5Grok 4.5
LMArena WebDev14181553
SciCode42.9%54.1%
WeirdML60.7%46.4%
LMArena Coding14361474
ALE-Bench1,1621,309
SWE-bench Verified73.6%—
DeepSWE—53.8%
FrontierCode—42.4%
SWE-bench Verified (bash only)65%—
Aider Polyglot88%—
GSO6.9%—
AlgoTune1.67—

Agentic & Tool Use Grok 4.5 leads

GPT-5: 33.1 (#56), Grok 4.5: 44.4 (#17)

Agentic & Tool Use benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Search11331213
Terminal-Bench49.6%—
APEX-Agents—56.2%
GDPval34.8%—
Remote Labor Index1.7%—
τ²-bench Banking—47.9%
DeepResearch Bench49.6%—
PostTrainBench—23.4%
BALROG32.8%—
GBAEval—65.4%
GDP.pdf—14%
METR Time Horizons69.6%—
Vending-Bench 2—3,887

Reasoning Grok 4.5 leads

GPT-5: 38.3 (#64), Grok 4.5: 56.1 (#25)

Reasoning benchmarks
BenchmarkGPT-5Grok 4.5
ARC-AGI-29.9%52.6%
SimpleBench56.7%70%
Kagi LLM Benchmark72.7%83.5%
ARC-AGI-165.7%87.2%
CritPt12.6%15.4%
Chess Puzzles37%36%
LMArena Hard Prompts14161462
DTBench90.7%96.5%
LMCA40%45.2%
Epoch Capabilities Index150153.92
NYT Connections (extended)—79.9%
EnigmaEval10.5%—
EBR-Bench12.7%—
Mystery Game Puzzles23%—
Surface Evolver Bench—74.4%
ForecastBench61.4—

Math Grok 4.5 leads

GPT-5: 55.0 (#44), Grok 4.5: 60.9 (#35)

Math benchmarks
BenchmarkGPT-5Grok 4.5
FrontierMath (Tiers 1-3)55.4%57.2%
FrontierMath Tier 422%24.4%
OTIS Mock AIME 2024-202591.4%97.8%
ProofBench18%31%
LMArena Math14071459
Omni-MATH64.7%—
MATH Level 598.1%—
FrontierMath (Feb 2025 set)32.4%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge Grok 4.5 leads

GPT-5: 56.6 (#43), Grok 4.5: 62.3 (#24)

Knowledge benchmarks
BenchmarkGPT-5Grok 4.5
GPQA Diamond86.2%93.4%
SimpleQA Verified50.1%48.3%
LMArena Expert14191466
Humanity's Last Exam25.3%—
MMLU-Pro86.3%—
Confabulations10.3%—
Vectara Hallucination Rate14.7%—
GPQA (HELM)79.2%—

Multimodal GPT-5 leads

GPT-5: 46.8 (#13), Grok 4.5: 37.6 (#72)

Multimodal benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Vision12321288
GeoBench81%—
VPCT66%—
Blueprint-Bench 2—27.3%
Furniture Assembly—22.5%
LMArena Document—1452

Multilingual Grok 4.5 leads

GPT-5: 51.4 (#110), Grok 4.5: 54.4 (#42)

Multilingual benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Non-English13971440
LMArena Chinese14221496
LMArena French14101456
LMArena German14161446
LMArena Japanese14091428
LMArena Korean13601404
LMArena Russian14061448
LMArena Spanish13991450

Instruction Following Grok 4.5 leads

GPT-5: 73.8 (#113), Grok 4.5: 76.0 (#48)

Instruction Following benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Instruction Following13881446
IFEval87.5%—

Long Context GPT-5 leads

GPT-5: 69.5 (#2), Grok 4.5: 44.8 (#56)

Long Context benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Longer Query13991463
Fiction.LiveBench97.2%—

Writing & Preference Grok 4.5 leads

GPT-5: 63.4 (#65), Grok 4.5: 65.8 (#42)

Writing & Preference benchmarks
BenchmarkGPT-5Grok 4.5
LMArena Text14061448
LMArena Creative Writing13651442
EQ-Bench Creative Writing16271579
LMArena Multi-Turn14261456
Short-Story Creative Writing86%—
WildBench85.7%—

Frequently asked questions

Is GPT-5 better than Grok 4.5?

Grok 4.5 is the stronger model overall, scoring 55.0 to 50.9 on the Noometry Index.

Which is cheaper, GPT-5 or Grok 4.5?

Grok 4.5 is cheaper. It lists at $2 per million input tokens and $6 per million output tokens; GPT-5 lists at $1.25 and $10.

Is GPT-5 or Grok 4.5 better for coding?

Grok 4.5 scores higher on coding benchmarks: 52.2 versus 50.3 in the Noometry coding category.

Which has the bigger context window?

Grok 4.5 does, with 500K tokens against 400K.

How many benchmarks do GPT-5 and Grok 4.5 share?

39 benchmarks have published results for both models. GPT-5 has 69 scored results on Noometry and Grok 4.5 has 52.

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