Noometry

Model comparison

Gemini 3.1 Pro Preview vs Grok 4.1 Fast

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 16× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Last verified . 31 shared benchmarks.

Gemini 3.1 Pro Preview Google

56.7

Rank #23 Confirmed

Grok 4.1 Fast xAI

41.4

Rank #136 Confirmed

Summary

  • They share 31 benchmarks with published results for both. Gemini 3.1 Pro Preview scores higher in 10 categories and Grok 4.1 Fast in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Gemini 3.1 Pro Preview leads 71.8 to 33.1.
  • The biggest single-benchmark swing is MathArena Final-Answer Competitions: 86.5% for Gemini 3.1 Pro Preview and 60.9% for Grok 4.1 Fast.
  • Grok 4.1 Fast is cheaper at $0.20 / $0.50 per million input/output tokens, against $2 / $12 for Gemini 3.1 Pro Preview.
  • Gemini 3.1 Pro Preview accepts more context: 1.05M tokens versus 128K.

Side by side

Gemini 3.1 Pro PreviewGrok 4.1 Fast
ProviderGooglexAI
Noometry Index56.741.4
Released2026-02-192025-06-27
WeightsProprietaryProprietary
Context window1.05M128K
Max output66K30K
Input $ / M tokens$2$0.20
Output $ / M tokens$12$0.50
Results tracked7132

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 42.5 (#99), Grok 4.1 Fast: 34.1 (#245)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena WebDev14471242
LMArena Coding14841411
ALE-Bench1,161394.93
SWE-bench Verified75.6%—
DeepSWE11.7%—
SciCode58.9%—
GSO22.6%—
WeirdML72.1%—
MirrorCode8.9%—
AlgoTune2.02—

Agentic & Tool Use Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 37.7 (#34), Grok 4.1 Fast: 36.3 (#39)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
τ²-bench Banking26%13.1%
LMArena Search12111171
Vending-Bench 23,7741,107
Terminal-Bench80.2%—
APEX-Agents35.3%—
Berkeley Function Calling Leaderboard—69.6%
DeepResearch Bench47.8%—
PostTrainBench22%—
BALROG57%—
ExploitBench26.1%—
GBAEval0.8%—
GDP.pdf17%—
METR Time Horizons77%—

Reasoning Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 71.7 (#12), Grok 4.1 Fast: 43.4 (#49)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
SimpleBench79.6%56%
NYT Connections (extended)97.4%87.4%
LMArena Hard Prompts14851407
DTBench97.1%87.7%
ForecastBench5961
ARC-AGI-277.1%—
ARC-AGI-198%—
CritPt17.7%—
Chess Puzzles55%—
EnigmaEval36.8%—
Thematic Generalization79.4%—
EBR-Bench14.3%—
Mystery Game Puzzles34%—
LMCA53.8%—
Epoch Capabilities Index154.77—

Math Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 62.1 (#34), Grok 4.1 Fast: 31.9 (#221)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
MathArena Final-Answer Competitions86.5%60.9%
ProofBench26%4%
LMArena Math14851408
FrontierMath (Tiers 1-3)59.6%—
FrontierMath Tier 426.8%—
OTIS Mock AIME 2024-202595.6%—
FrontierMath (Feb 2025 set)36.9%—
FrontierMath Tier 4 (v1)16.7%—

Knowledge Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 71.8 (#3), Grok 4.1 Fast: 33.1 (#207)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
Vectara Hallucination Rate10.4%17.8%
LMArena Expert14851399
GPQA Diamond94.4%—
Humanity's Last Exam46.4%—
SimpleQA Verified73.5%—

Multimodal Too close to call

Gemini 3.1 Pro Preview: 37.9 (#69), Grok 4.1 Fast: 37.0 (#76)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena Vision12961201
Blueprint-Bench 226.5%—
Furniture Assembly26.7%—
LMArena Document1444—

Multilingual Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 57.0 (#12), Grok 4.1 Fast: 51.0 (#114)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena Non-English14771391
LMArena Chinese15291441
LMArena French14871415
LMArena German14911404
LMArena Japanese14931349
LMArena Korean14551361
LMArena Russian14981387
LMArena Spanish14791413

Instruction Following Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 77.0 (#32), Grok 4.1 Fast: 72.7 (#133)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena Instruction Following14661376

Long Context Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 47.4 (#18), Grok 4.1 Fast: 42.4 (#126)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena Longer Query14831390
CL-bench20.8%—
CL-bench Life16.9%—

Writing & Preference Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 66.1 (#37), Grok 4.1 Fast: 57.2 (#131)

BenchmarkGemini 3.1 Pro PreviewGrok 4.1 Fast
LMArena Text14811408
LMArena Creative Writing14821394
EQ-Bench Creative Writing14911327
LMArena Multi-Turn14881389
EQ-Bench 41142—

Frequently asked questions

Is Gemini 3.1 Pro Preview better than Grok 4.1 Fast?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 41.4 on the Noometry Index. Grok 4.1 Fast costs 16× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Which is cheaper, Gemini 3.1 Pro Preview 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 3.1 Pro Preview lists at $2 and $12.

Is Gemini 3.1 Pro Preview or Grok 4.1 Fast better for coding?

Gemini 3.1 Pro Preview scores higher on coding benchmarks: 42.5 versus 34.1 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.1 Pro Preview does, with 1.05M tokens against 128K.

How many benchmarks do Gemini 3.1 Pro Preview and Grok 4.1 Fast share?

31 benchmarks have published results for both models. Gemini 3.1 Pro Preview has 71 scored results on Noometry and Grok 4.1 Fast has 32.

Related comparisons

Go deeper