Noometry

Model comparison

GPT-5.5 Instant vs Grok 4

Grok 4 is the stronger model overall, scoring 48.1 to 42.7 on the Noometry Index.

Last verified . 22 shared benchmarks.

GPT-5.5 Instant OpenAI

42.7

Rank #110 Confirmed

Grok 4 xAI

48.1

Rank #56 Confirmed

Summary

  • They share 22 benchmarks with published results for both. GPT-5.5 Instant scores higher in 3 categories and Grok 4 in 6 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Grok 4 leads 48.4 to 26.5.
  • The biggest single-benchmark swing is Chess Puzzles: 12% for GPT-5.5 Instant and 28% for Grok 4.

Side by side

GPT-5.5 InstantGrok 4
ProviderOpenAIxAI
Noometry Index42.748.1
Released2026-05-052025-07-09
WeightsProprietaryProprietary
Context window——
Max output——
Input $ / M tokens——
Output $ / M tokens——
Results tracked2748

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Category by category

Coding Grok 4 leads

GPT-5.5 Instant: 44.3 (#74), Grok 4: 50.3 (#46)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Coding14331408
Aider Polyglot—79.6%
SciCode48.6%—
WeirdML—45.7%

Agentic & Tool Use Not comparable

GPT-5.5 Instant: —, Grok 4: 32.3 (#68)

BenchmarkGPT-5.5 InstantGrok 4
Terminal-Bench—27.2%
Berkeley Function Calling Leaderboard—63%
GDPval—21.1%
Cybench—43%
DeepResearch Bench—47.3%
BALROG—43.6%
LMArena Search—1142
METR Time Horizons—66.6%

Reasoning Grok 4 leads

GPT-5.5 Instant: 24.9 (#155), Grok 4: 36.7 (#65)

BenchmarkGPT-5.5 InstantGrok 4
Chess Puzzles12%28%
LMArena Hard Prompts14261409
Epoch Capabilities Index142.52146.44
ARC-AGI-2—16%
SimpleBench—60.5%
Kagi LLM Benchmark—73.6%
ARC-AGI-1—66.7%
CritPt0%—
ForecastBench—60.9

Math Grok 4 leads

GPT-5.5 Instant: 26.5 (#259), Grok 4: 48.4 (#64)

BenchmarkGPT-5.5 InstantGrok 4
OTIS Mock AIME 2024-202568.1%84%
LMArena Math14201422
FrontierMath (Tiers 1-3)26.3%—
FrontierMath Tier 42.4%—
Omni-MATH—60.3%
FrontierMath (Feb 2025 set)—19.7%
FrontierMath Tier 4 (v1)—2.1%

Knowledge Grok 4 leads

GPT-5.5 Instant: 48.9 (#74), Grok 4: 53.8 (#55)

BenchmarkGPT-5.5 InstantGrok 4
GPQA Diamond82.5%87%
LMArena Expert14091415
MMLU-Pro—85.1%
Confabulations—12.4%
GPQA (HELM)—72.7%

Multimodal GPT-5.5 Instant leads

GPT-5.5 Instant: 40.0 (#52), Grok 4: 33.7 (#94)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Vision12501210
GeoBench—45%
LMArena Document1403—

Multilingual GPT-5.5 Instant leads

GPT-5.5 Instant: 52.8 (#80), Grok 4: 51.8 (#103)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Non-English14171403
LMArena Chinese14561427
LMArena French14281418
LMArena German14111429
LMArena Japanese14081394
LMArena Korean13921377
LMArena Russian14311410
LMArena Spanish14291420

Instruction Following Grok 4 leads

GPT-5.5 Instant: 74.2 (#100), Grok 4: 79.2 (#5)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Instruction Following14061387
IFEval—94.9%

Long Context Grok 4 leads

GPT-5.5 Instant: 43.4 (#96), Grok 4: 63.1 (#4)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Longer Query14221409
Fiction.LiveBench—94.4%

Writing & Preference GPT-5.5 Instant leads

GPT-5.5 Instant: 61.8 (#85), Grok 4: 58.5 (#116)

BenchmarkGPT-5.5 InstantGrok 4
LMArena Text14191411
LMArena Creative Writing14191397
LMArena Multi-Turn14331416
Short-Story Creative Writing—76.9%
WildBench—79.7%

Frequently asked questions

Is GPT-5.5 Instant better than Grok 4?

Grok 4 is the stronger model overall, scoring 48.1 to 42.7 on the Noometry Index.

Is GPT-5.5 Instant or Grok 4 better for coding?

Grok 4 scores higher on coding benchmarks: 50.3 versus 44.3 in the Noometry coding category.

How many benchmarks do GPT-5.5 Instant and Grok 4 share?

22 benchmarks have published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and Grok 4 has 48.

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