Noometry

Model comparison

Gemini 3.1 Pro Preview vs Grok 4.5

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 55.0 on the Noometry Index. Grok 4.5 costs 1.5× 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 . 49 shared benchmarks.

Gemini 3.1 Pro Preview Google

56.7

Rank #23 Confirmed

Grok 4.5 xAI

55.0

Rank #25 Confirmed

Summary

  • They share 49 benchmarks with published results for both. Gemini 3.1 Pro Preview scores higher in 8 categories and Grok 4.5 in 2 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.1 Pro Preview leads 71.7 to 56.1.
  • The biggest single-benchmark swing is GBAEval: 0.8% for Gemini 3.1 Pro Preview and 65.4% for Grok 4.5.
  • Grok 4.5 is cheaper at $2 / $6 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 500K.

Side by side

Gemini 3.1 Pro PreviewGrok 4.5
ProviderGooglexAI
Noometry Index56.755.0
Released2026-02-192026-07-08
WeightsProprietaryProprietary
Context window1.05M500K
Max output66K500K
Input $ / M tokens$2$2
Output $ / M tokens$12$6
Results tracked7152

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Category by category

Coding Grok 4.5 leads

Gemini 3.1 Pro Preview: 42.5 (#99), Grok 4.5: 52.2 (#35)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
DeepSWE11.7%53.8%
LMArena WebDev14471553
SciCode58.9%54.1%
WeirdML72.1%46.4%
LMArena Coding14841474
ALE-Bench1,1611,309
SWE-bench Verified75.6%—
FrontierCode—42.4%
GSO22.6%—
MirrorCode8.9%—
AlgoTune2.02—

Agentic & Tool Use Grok 4.5 leads

Gemini 3.1 Pro Preview: 37.7 (#34), Grok 4.5: 44.4 (#17)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
APEX-Agents35.3%56.2%
τ²-bench Banking26%47.9%
PostTrainBench22%23.4%
GBAEval0.8%65.4%
GDP.pdf17%14%
LMArena Search12111213
Vending-Bench 23,7743,887
Terminal-Bench80.2%—
DeepResearch Bench47.8%—
BALROG57%—
ExploitBench26.1%—
METR Time Horizons77%—

Reasoning Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 71.7 (#12), Grok 4.5: 56.1 (#25)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
ARC-AGI-277.1%52.6%
SimpleBench79.6%70%
NYT Connections (extended)97.4%79.9%
ARC-AGI-198%87.2%
CritPt17.7%15.4%
Chess Puzzles55%36%
LMArena Hard Prompts14851462
DTBench97.1%96.5%
LMCA53.8%45.2%
Epoch Capabilities Index154.77153.92
Kagi LLM Benchmark—83.5%
EnigmaEval36.8%—
Thematic Generalization79.4%—
EBR-Bench14.3%—
Mystery Game Puzzles34%—
Surface Evolver Bench—74.4%
ForecastBench59—

Math Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 62.1 (#34), Grok 4.5: 60.9 (#35)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
FrontierMath (Tiers 1-3)59.6%57.2%
FrontierMath Tier 426.8%24.4%
OTIS Mock AIME 2024-202595.6%97.8%
ProofBench26%31%
LMArena Math14851459
MathArena Final-Answer Competitions86.5%—
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 4.5: 62.3 (#24)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
GPQA Diamond94.4%93.4%
SimpleQA Verified73.5%48.3%
LMArena Expert14851466
Humanity's Last Exam46.4%—
Vectara Hallucination Rate10.4%—

Multimodal Too close to call

Gemini 3.1 Pro Preview: 37.9 (#69), Grok 4.5: 37.6 (#72)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
LMArena Vision12961288
Blueprint-Bench 226.5%27.3%
Furniture Assembly26.7%22.5%
LMArena Document14441452

Multilingual Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 57.0 (#12), Grok 4.5: 54.4 (#42)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
LMArena Non-English14771440
LMArena Chinese15291496
LMArena French14871456
LMArena German14911446
LMArena Japanese14931428
LMArena Korean14551404
LMArena Russian14981448
LMArena Spanish14791450

Instruction Following Too close to call

Gemini 3.1 Pro Preview: 77.0 (#32), Grok 4.5: 76.0 (#48)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
LMArena Instruction Following14661446

Long Context Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 47.4 (#18), Grok 4.5: 44.8 (#56)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
LMArena Longer Query14831463
CL-bench20.8%—
CL-bench Life16.9%—

Writing & Preference Too close to call

Gemini 3.1 Pro Preview: 66.1 (#37), Grok 4.5: 65.8 (#42)

BenchmarkGemini 3.1 Pro PreviewGrok 4.5
LMArena Text14811448
LMArena Creative Writing14821442
EQ-Bench Creative Writing14911579
LMArena Multi-Turn14881456
EQ-Bench 41142—

Frequently asked questions

Is Gemini 3.1 Pro Preview better than Grok 4.5?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 55.0 on the Noometry Index. Grok 4.5 costs 1.5× 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 4.5?

Grok 4.5 is cheaper. It lists at $2 per million input tokens and $6 per million output tokens; Gemini 3.1 Pro Preview lists at $2 and $12.

Is Gemini 3.1 Pro Preview or Grok 4.5 better for coding?

Grok 4.5 scores higher on coding benchmarks: 52.2 versus 42.5 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.1 Pro Preview does, with 1.05M tokens against 500K.

How many benchmarks do Gemini 3.1 Pro Preview and Grok 4.5 share?

49 benchmarks have published results for both models. Gemini 3.1 Pro Preview has 71 scored results on Noometry and Grok 4.5 has 52.

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