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Gemini 3.1 Pro Preview vs Grok 4.20

vs
Grok 4.20

xAI

89#29
Signal-by-Signal Comparison
SignalGemini 3.1 Pro PreviewDeltaGrok 4.20
Capabilities
100
--
100
Benchmarks
92
+5
86
Pricing
88
-9
98
Context window size
96
-4
100
Recency
100
--
100
Output Capacity
80
+60
20
Overall Result
2 wins
of 6
2 wins
It's a tie - both models win 2 signals each

Score History

Score History (24 data points)
Gemini 3.1 Pro PreviewGrok 4.20
Gemini 3.1 Pro Preview

92.2

current score

Leader

Gemini 3.1 Pro Preview

right now

Grok 4.20

88.8

current score

LMMarketCap.com
Interactive Price Comparison
100Kcalls/month
1,000tokens (~1,333 chars)
500tokens (~667 chars)

Gemini 3.1 Pro Preview

Google

Per request$0.008000
Daily$26.67
Monthly$800.00
Annual$9600.00

Grok 4.20

xAI

Best Value
Per request$0.002500
Daily$8.33
Monthly$250.00
Annual$3000.00

Grok 4.20 saves you $550.00/month

That's $6600.00/year compared to Gemini 3.1 Pro Preview at your current usage level of 100K calls/month.

69% cheaper
Choose Grok 4.20 for cost optimization

Gemini 3.1 Pro Preview pricing:
Input:$2.00/M tokens
Output:$12.00/M tokens
Grok 4.20 pricing:
Input:$1.25/M tokens
Output:$2.50/M tokens
Winner
Gemini 3.1 Pro Preview

Google

92

Composite Score

Grok 4.20

xAI

89

Composite Score

Signal-by-Signal Comparison
MetricGemini 3.1 Pro PreviewGrok 4.20Winner
Overall Score
92
89
Gemini 3.1 Pro Preview
Rank#11#29
Gemini 3.1 Pro Preview
Quality Rank#11#29
Gemini 3.1 Pro Preview
Adoption Rank#11#29
Gemini 3.1 Pro Preview
Parameters------
Context Window1049K2000K
Grok 4.20
Pricing$2.00/$12.00/M$1.25/$2.50/M--
Signal Scores
Capabilities
100
100
Gemini 3.1 Pro Preview
Benchmarks
92
86
Gemini 3.1 Pro Preview
Pricing
88
98
Grok 4.20
Context window size
96
100
Grok 4.20
Recency
100
100
Gemini 3.1 Pro Preview
Output Capacity
80
20
Gemini 3.1 Pro Preview
Benchmark Head-to-Head(11 benchmarks)
Gemini 3.1: 5Grok 4.20: 0
Gemini 3.1
Grok 4.20
Normalized 0-100%
MMLU
92.6%91.5%
MMLU-Pro
91.2%83.5%
GPQA Diamond
94.3%82%
MATH-500
-95%
HumanEval
-95.5%
SWE-bench Verified
80.6%70%
AIME 2024
-88%
IFEval
-91%
BBH
-90%
Arena Elo
14941462
LiveBench
-73%
Benchmark Interpretation

Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.

Gemini 3.1 Pro PreviewElite Tier

Scores 92/100 (rank #11), placing it in the top 97% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
Grok 4.20Elite Tier

Scores 89/100 (rank #29), placing it in the top 90% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

With only a 3-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.

When to Use Each Model

Choose Gemini 3.1 Pro Preview when you need:

  • Step-by-step reasoning and chain-of-thought problem solving

Choose Grok 4.20 when you need:

  • High-volume production workloads where API costs must be minimized
  • Processing long documents or large codebases (2000K token context)
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
Gemini 3.1 Pro Preview
Input cost$2.00/M tokens
Output cost$12.00/M tokens
Cost per quality point$0.152
Est. monthly (1M tokens/day)$210.00
Grok 4.20Best Value
Input cost$1.25/M tokens
Output cost$2.50/M tokens
Cost per quality point$0.042
Est. monthly (1M tokens/day)$56.25

Grok 4.20 offers 73% better value per quality point. At 1M tokens/day, you'd spend $56.25/month with Grok 4.20 vs $210.00/month with Gemini 3.1 Pro Preview - a $153.75 monthly difference.

Latency & Speed
Gemini 3.1 Pro PreviewFaster
Speed score0/100
Grok 4.20
Speed score0/100

Both models have comparable response speeds. For most applications, the latency difference is negligible.

When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.

Example Use Cases

Code generation & review

Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring

Gemini 3.1 Pro Preview

Customer support chatbot

Suitable for user-facing chat with competitive response times. Grok 4.20 also offers lower per-token costs for high-volume support

Gemini 3.1 Pro Preview

Long document analysis

Larger context window (2000K tokens) can process longer documents, contracts, and research papers in a single pass

Grok 4.20

Batch data extraction

Lower output pricing ($2.50/M) reduces costs when processing thousands of records daily

Grok 4.20

Creative writing & content

Higher overall composite score (92/100) correlates with better nuance, coherence, and style in long-form content

Gemini 3.1 Pro Preview

Image understanding & OCR

Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly

Gemini 3.1 Pro Preview
Which Should You Choose?
Our recommendation:
Gemini 3.1 Pro Preview

Gemini 3.1 Pro Preview has a moderate advantage with a 3.4000000000000057-point lead in composite score. It wins on more signal dimensions, but Grok 4.20 has specific strengths that could make it the better choice for certain workflows.

by Google

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Reliability - Higher uptime and faster response speeds
  • Choose for Prototyping - Stronger community support and better developer experience
  • Choose for Production - Wider enterprise adoption and proven at scale

by xAI

  • Choose for Cost - 73% lower pricing; better value at scale
Capability Comparison
CapabilityGemini 3.1 Pro PreviewGrok 4.20
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoning
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

Gemini 3.1 Pro Preview

Google

$18.00
estimated monthly cost

Grok 4.20

xAI

Best Value
$5.25
estimated monthly cost

Grok 4.20 saves you $12.75/month

That's 71% cheaper than Gemini 3.1 Pro Preview at 1,000 tokens/request and 100 requests/day.

Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.

Parameters & Context
ParameterGemini 3.1 Pro PreviewGrok 4.20
Context Window1.0M2M
Max Output Tokens65,536--
Open SourceNoNo
CreatedFeb 19, 2026Mar 31, 2026
Last updated: 56m ago

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