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Model comparison

Gemini 3.1 Pro vs Grok 4.20

Data verified

Head-to-head evidence from 16 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

54.66/100
Margin
0.8pts
← winning
53.88/100
2 category wins0 category wins

Public leaderboard positions: Gemini 3.1 Pro #87 (Estimated); Grok 4.20 #93 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Gemini 3.1 Pro and Grok 4.20 share 16 comparable benchmark results. 2 of 8 categories are comparable. 26 results are unique to Gemini 3.1 Pro; 3 to Grok 4.20.

Updated July 28, 2026
Shared results
16
Gemini 3.1 Pro only
26
Grok 4.20 only
3
Comparable categories
2 / 8

Pick Gemini 3.1 Pro if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you want the cheaper token bill or you need the larger 2M context window.

Confidence note. This is a partial-evidence comparison with 16 shared benchmark results across 5 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Gemini 3.1 Pro has the cleaner BenchAlign overall profile here, landing at 54.66 versus 53.88. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Gemini 3.1 Pro's sharpest advantage is in reasoning, where it averages 77.1 against 53.3. The single biggest benchmark swing on the page is ARC-AGI-2, 77.1% to 53.3%.

Gemini 3.1 Pro is also the more expensive model on tokens at $2.00 input / $12.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.20. That is roughly 2.0x on output cost alone. Grok 4.20 gives you the larger context window at 2M, compared with 1M for Gemini 3.1 Pro.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Gemini 3.1 Pro and Grok 4.20
CategoryGemini 3.1 ProΔGrok 4.20
ReasoningGemini 3.1 Pro77.1Margin← 23.8Grok 4.2053.3
MultimodalGemini 3.1 Pro82.6Margin← 12.5Grok 4.2070.1
AgenticGemini 3.1 ProNot measuredMarginNo overlapGrok 4.2047.1
CodingGemini 3.1 ProNot measuredMarginNo overlapGrok 4.2067.1
MathGemini 3.1 Pro31.8MarginNo overlapGrok 4.20Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Gemini 3.1 ProB · Grok 4.20

  1. ARC-AGI-2

    Reasoning
    Source ↗
    A 77.1%B 53.3%
    Winner: Gemini 3.1 ProΔ 23.8
    ARC-AGI-2: Gemini 3.1 Pro scored 77.1%; Grok 4.20 scored 53.3%. Gemini 3.1 Pro wins this benchmark.

  2. CharXiv

    Multimodal
    Source ↗
    A 80.2%B 60.9%
    Winner: Gemini 3.1 ProΔ 19.3
    CharXiv: Gemini 3.1 Pro scored 80.2%; Grok 4.20 scored 60.9%. Gemini 3.1 Pro wins this benchmark.

  3. MMMU-Pro

    Multimodal
    Source ↗
    A 83.9%B 75.2%
    Winner: Gemini 3.1 ProΔ 8.7
    MMMU-Pro: Gemini 3.1 Pro scored 83.9%; Grok 4.20 scored 75.2%. Gemini 3.1 Pro wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGemini 3.1 ProGrok 4.20Comparison
Input / output priceUSD per 1M tokensGemini 3.1 Pro$2 input / $12 outputGrok 4.20$2 input / $6 outputGrok 4.20 has the lower combined listed price.
Generation speedtokens per secondGemini 3.1 Pro109 tok/sGrok 4.20233 tok/sGrok 4.20 has the higher measured throughput.
First-answer latencyseconds to first tokenGemini 3.1 Pro29.71 sGrok 4.2010.33 sGrok 4.20 reaches the first token sooner.
Context windowmaximum listed tokensGemini 3.1 Pro1MGrok 4.202MGrok 4.20 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGemini 3.1 ProGrok 4.20Result
Claw-EvalSource 57.8%—Not comparable
DeepSearchQASource 69.7%62.8%Gemini 3.1 Pro leads
τ²-bench resultsSource 95.6%—Not comparable
AA Agentic IndexSource 21.4%—Not comparable
APEX-Agents-AASource 32.0%—Not comparable
GDPval-AASource 23.2%—Not comparable
GDPval-AASource 965—Not comparable
Gert LabsSource 56.87%38.36%Gemini 3.1 Pro leads
ResearchClawBenchSource 13.3%—Not comparable
AA AutomationBenchSource 37.5%—Not comparable
Terminal-Bench 2.0Source —47.1%Not comparable
Coding
BenchmarkGemini 3.1 ProGrok 4.20Result
LiveCodeBench ProSource 82.9%74.2%Gemini 3.1 Pro leads
React Native EvalsSource 78.9%—Not comparable
Vibe Code BenchSource 32.03%4.06%Gemini 3.1 Pro leads
AA Coding IndexSource 68.8%—Not comparable
AA-SciCodeSource 58.9%—Not comparable
SWE-bench VerifiedSource —76.7%Not comparable
SWE-bench ProSource —51.8%Not comparable
ReasoningGemini 3.1 Pro wins
BenchmarkGemini 3.1 ProGrok 4.20Result
ARC-AGI-2Source 77.1%53.3%Gemini 3.1 Pro leads
ARC-AGI-3Source 0.4%0.1%Gemini 3.1 Pro leads
AA-LCRSource 72.7%—Not comparable
CritPtSource 17.7%—Not comparable
Knowledge
BenchmarkGemini 3.1 ProGrok 4.20Result
GPQA-DSource 94.3%88.5%Gemini 3.1 Pro leads
HLE w/o toolsSource 45.4%31.6%Gemini 3.1 Pro leads
HealthBench HardSource 20.6%20.3%Gemini 3.1 Pro leads
MedXpertQA (Text)Source 71.5%50.2%Gemini 3.1 Pro leads
Artificial Analysis Intelligence IndexSource 46.5%—Not comparable
AA-GPQA DiamondSource 94.1%—Not comparable
AA-HLESource 44.7%—Not comparable
AA-Omniscience IndexSource 32.9%—Not comparable
AA-Omniscience AccuracySource 55.3%—Not comparable
AA-Omniscience Hallucination RateSource 49.9%—Not comparable
Math
BenchmarkGemini 3.1 ProGrok 4.20Result
FrontierMath v2 (Tiers 1-3)Source 36.900%—Not comparable
FrontierMath v2 (Tier 4)Source 16.700%—Not comparable
Multilingual
BenchmarkGemini 3.1 ProGrok 4.20Result
AA Global-MMLU-LiteSource 93.2%—Not comparable
MultimodalGemini 3.1 Pro wins
BenchmarkGemini 3.1 ProGrok 4.20Result
MMMU-ProSource 83.9%75.2%Gemini 3.1 Pro leads
CharXivSource 80.2%60.9%Gemini 3.1 Pro leads
ERQASource 69.4%54.1%Gemini 3.1 Pro leads
SimpleVQASource 72.4%57.4%Gemini 3.1 Pro leads
ScreenSpot ProSource 84.4%—Not comparable
ZeroBenchSource 29.0%—Not comparable
MedXpertQA (MM)Source 81.3%65.8%Gemini 3.1 Pro leads
AA-MMMU-ProSource 82.4%—Not comparable
Design Arena WebsiteSource 12761252Gemini 3.1 Pro leads
Inst. Following
BenchmarkGemini 3.1 ProGrok 4.20Result
AA-IFBenchSource 77.1%—Not comparable
Frequently Asked Questions (3)

Which is better, Gemini 3.1 Pro or Grok 4.20?

Gemini 3.1 Pro is ahead on BenchLM's BenchAlign leaderboard, 54.66 to 53.88. The biggest single separator in this matchup is ARC-AGI-2, where the scores are 77.1% and 53.3%.

Which is better for reasoning, Gemini 3.1 Pro or Grok 4.20?

Gemini 3.1 Pro has the edge for reasoning in this comparison, averaging 77.1 versus 53.3. Inside this category, ARC-AGI-2 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Gemini 3.1 Pro or Grok 4.20?

Gemini 3.1 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 82.6 versus 70.1. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

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