Noometry

Model comparison

Gemini 2.5 Pro vs Grok 4.1 Fast

Gemini 2.5 Pro is the stronger model overall, scoring 45.0 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 12× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

Last verified . 28 shared benchmarks.

Gemini 2.5 Pro Google

45.0

Rank #75 Confirmed

Grok 4.1 Fast xAI

41.4

Rank #136 Confirmed

Summary

  • They share 28 benchmarks with published results for both. Gemini 2.5 Pro scores higher in 8 categories and Grok 4.1 Fast in 2 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Gemini 2.5 Pro leads 56.0 to 33.1.
  • The biggest single-benchmark swing is Vectara Hallucination Rate: 7% for Gemini 2.5 Pro and 17.8% for Grok 4.1 Fast.
  • Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $1.25 / $10 for Gemini 2.5 Pro.
  • Gemini 2.5 Pro accepts more context: 1.05M tokens versus 128K.

Side by side

Gemini 2.5 ProGrok 4.1 Fast
ProviderGooglexAI
Noometry Index45.041.4
Released2025-03-252025-06-27
WeightsProprietaryProprietary
Context window1.05M128K
Max output66K30K
Input $ / M tokens$1.25$0.20
Output $ / M tokens$10$0.50
Results tracked7832

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Category by category

Coding Gemini 2.5 Pro leads

Gemini 2.5 Pro: 42.4 (#101), Grok 4.1 Fast: 34.1 (#245)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena WebDev12271242
LMArena Coding14521411
ALE-Bench785.52394.93
SWE-bench Verified57.6%—
SWE-bench Verified (bash only)53.6%—
Aider Polyglot83.1%—
SciCode42.8%—
GSO3.9%—
WeirdML54%—
LiveBench Coding85.9%—
CadEval64%—
AlgoTune1.51—

Agentic & Tool Use Grok 4.1 Fast leads

Gemini 2.5 Pro: 29.2 (#88), Grok 4.1 Fast: 36.3 (#39)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
τ²-bench Banking13.7%13.1%
LMArena Search11421171
Vending-Bench 2573.641,107
Terminal-Bench32.6%—
Berkeley Function Calling Leaderboard—69.6%
GDPval23.3%—
Remote Labor Index0.8%—
TheAgentCompany30.3%—
DeepResearch Bench42.8%—
BALROG43.3%—
METR Time Horizons55.4%—

Reasoning Grok 4.1 Fast leads

Gemini 2.5 Pro: 28.8 (#99), Grok 4.1 Fast: 43.4 (#49)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
SimpleBench62.4%56%
LMArena Hard Prompts14551407
DTBench82.4%87.7%
ForecastBench61.361
ARC-AGI-24.9%—
Kagi LLM Benchmark70.3%—
NYT Connections (extended)—87.4%
ARC-AGI-141%—
CritPt2%—
Chess Puzzles20%—
EnigmaEval5.6%—
LiveBench Reasoning89.8%—
LiveBench Data Analysis79.9%—
LMCA34.8%—
Epoch Capabilities Index145.32—
LiveBench82.3%—

Math Too close to call

Gemini 2.5 Pro: 32.5 (#213), Grok 4.1 Fast: 31.9 (#221)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Math14501408
FrontierMath (Tiers 1-3)24.6%—
FrontierMath Tier 40%—
MathArena Final-Answer Competitions—60.9%
OTIS Mock AIME 2024-202584.7%—
ProofBench—4%
Omni-MATH41.6%—
LiveBench Math90.2%—
MATH Level 595.9%—
FrontierMath (Feb 2025 set)14.1%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Gemini 2.5 Pro leads

Gemini 2.5 Pro: 56.0 (#46), Grok 4.1 Fast: 33.1 (#207)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
Vectara Hallucination Rate7%17.8%
LMArena Expert14521399
GPQA Diamond85.3%—
Humanity's Last Exam21.6%—
MMLU-Pro86.3%—
Confabulations10.6%—
GPQA (HELM)74.9%—

Multimodal Gemini 2.5 Pro leads

Gemini 2.5 Pro: 45.2 (#18), Grok 4.1 Fast: 37.0 (#76)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Vision12631201
GeoBench86%—
VPCT48%—
LMArena Document1421—
SpatialViz-Bench44.7%—

Multilingual Gemini 2.5 Pro leads

Gemini 2.5 Pro: 55.3 (#31), Grok 4.1 Fast: 51.0 (#114)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Non-English14511391
LMArena Chinese15071441
LMArena French14721415
LMArena German14871404
LMArena Japanese14611349
LMArena Korean14341361
LMArena Russian14611387
LMArena Spanish14731413

Instruction Following Gemini 2.5 Pro leads

Gemini 2.5 Pro: 75.0 (#75), Grok 4.1 Fast: 72.7 (#133)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Instruction Following14371376
LiveBench Instruction Following80.6%—
IFEval84%—

Long Context Gemini 2.5 Pro leads

Gemini 2.5 Pro: 59.8 (#5), Grok 4.1 Fast: 42.4 (#126)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Longer Query14491390
Fiction.LiveBench91.7%—

Writing & Preference Gemini 2.5 Pro leads

Gemini 2.5 Pro: 63.7 (#62), Grok 4.1 Fast: 57.2 (#131)

BenchmarkGemini 2.5 ProGrok 4.1 Fast
LMArena Text14581408
LMArena Creative Writing14541394
EQ-Bench Creative Writing14211327
LMArena Multi-Turn14531389
Short-Story Creative Writing83.8%—
WildBench85.7%—
LiveBench Language67.8%—

Frequently asked questions

Is Gemini 2.5 Pro better than Grok 4.1 Fast?

Gemini 2.5 Pro is the stronger model overall, scoring 45.0 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 12× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

Which is cheaper, Gemini 2.5 Pro or Grok 4.1 Fast?

Grok 4.1 Fast is cheaper. It lists at $0.20 per million input tokens and $0.50 per million output tokens; Gemini 2.5 Pro lists at $1.25 and $10.

Is Gemini 2.5 Pro or Grok 4.1 Fast better for coding?

Gemini 2.5 Pro scores higher on coding benchmarks: 42.4 versus 34.1 in the Noometry coding category.

Which has the bigger context window?

Gemini 2.5 Pro does, with 1.05M tokens against 128K.

How many benchmarks do Gemini 2.5 Pro and Grok 4.1 Fast share?

28 benchmarks have published results for both models. Gemini 2.5 Pro has 78 scored results on Noometry and Grok 4.1 Fast has 32.

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