Gemini 3.1 Pro vs Grok 4.20
Wins 6 of 8 areas
Coding · Reasoning · Facts · Images and charts · Math · Long documents
Wins 1 of 8 areas
Following instructions
Gemini 3.1 Pro is the stronger all-rounder.Grok 4.20 is cheaper and better at following instructions.
Scores updated · 23 tests both models report · How we compare
Where each one wins
Tests won in each of the eight areas we test. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking40Gemini 3.1 Pro4 of 4 tests
- CodingWriting and fixing software20Gemini 3.1 Pro2 of 2 tests
- MathCompetition and research-level math20Gemini 3.1 Pro2 of 2 tests
- FactsGetting facts right instead of making them up21Gemini 3.1 Pro2 of 3 tests
- Images and chartsUnderstanding pictures, charts and video10Gemini 3.1 Pro1 of 1 test
- Long documentsFinding answers in very long texts10Gemini 3.1 Pro1 of 1 test
- Following instructionsDoing exactly what it is asked01Grok 4.201 of 1 test
- AgentsCarrying out multi-step tasks on its own11Even1 each
Images and charts, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Grok 4.20 costs 73% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Gemini 3.1 Pro pulls ahead
- Short factual questions, answered correctlySimpleQA Verified+43.3points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+26points ahead
- Long professional tasks in banking, consulting and lawAA ApexAgents+17.8points ahead
Where Grok 4.20 pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+28.5points ahead
- Real work tasks from 44 professionsGDPVal+12.3points ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+5.8points ahead
Every test, side by side
All 23 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGemini 3.1 Pro
- SciCodeGemini 3.1 Pro by 1458.744.7+14
- Terminal-Bench HardGemini 3.1 Pro by 12.953.840.9+12.9
AgentsEven
- AA ApexAgentsGemini 3.1 Pro by 17.83214.2+17.8
- GDPValGrok 4.20 by 12.314.727+12.3
ReasoningGemini 3.1 Pro
- Humanity's Last ExamGemini 3.1 Pro by 14.64732.4+14.6
- ARC-AGI-2Gemini 3.1 Pro by 1277.165.1+12
- CritPtGemini 3.1 Pro by 11.717.76+11.7
- GPQA DiamondGemini 3.1 Pro by 5.694.188.5+5.6
FactsGemini 3.1 Pro
- SimpleQA VerifiedGemini 3.1 Pro by 43.373.530.2+43.3
- AA-Omniscience · Non-hallucinationGrok 4.20 by 28.549.177.6+28.5
- AA-Omniscience · AccuracyGemini 3.1 Pro by 2654.928.9+26
Images and chartsGemini 3.1 Pro
- MMMU-ProGemini 3.1 Pro by 9.282.473.2+9.2
MathGemini 3.1 Pro
- FrontierMath Tiers 1-3 (v2)Gemini 3.1 Pro by 14.859.644.9+14.8
- FrontierMath Tier 4Gemini 3.1 Pro by 9.726.817.1+9.7
Following instructionsGrok 4.20
- IFBenchGrok 4.20 by 5.877.182.9+5.8
Other results7 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- AA Agentic IndexGrok 4.20 by 40.610.350.9+40.6
- Artificial Analysis Coding IndexGemini 3.1 Pro by 26.668.842.2+26.6
- AA-OmniscienceGemini 3.1 Pro by 18.931.912.9+18.9
- HiL-Bench (Tools-allowed)Gemini 3.1 Pro by 15.335.320+15.3
- ARC-AGI-1Gemini 3.1 Pro by 8.59889.5+8.5
- AA IntelligenceGemini 3.1 Pro by 4.529.725.2+4.5
- τ²-Bench Telecom (AA run)tie95.696.5tie
Questions people ask
Which is better, Gemini 3.1 Pro or Grok 4.20?
Gemini 3.1 Pro wins six of the eight areas we test: coding, reasoning, facts, images and charts, math and long documents. Grok 4.20 wins following instructions, and costs 73% less. They are level on agents.
Which is better for coding?
Gemini 3.1 Pro. It wins 2 of the 2 coding tests both models report; Grok 4.20 wins none.
Which is cheaper?
Gemini 3.1 Pro costs $2.00 per million input tokens and $12.00 per million output tokens; Grok 4.20 costs $1.25 and $2.50. That makes Grok 4.20 about 73% cheaper for the same work.
How do you compare the two?
We use the 23 benchmark tests both models have published scores on. The verdict counts the 16 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 7 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.