Gemini 3.1 Pro vs Grok 4.1 Fast
Wins 8 of 8 areas
Coding · Agents · Reasoning · Facts · Images and charts · Math · Long documents · Following instructions
Wins 0 of 8 areas
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Gemini 3.1 Pro is the stronger all-rounder.Grok 4.1 Fast is cheaper.
Scores updated · 28 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 software30Gemini 3.1 Pro3 of 3 tests
- FactsGetting facts right instead of making them up30Gemini 3.1 Pro3 of 3 tests
- Images and chartsUnderstanding pictures, charts and video20Gemini 3.1 Pro2 of 2 tests
- MathCompetition and research-level math20Gemini 3.1 Pro2 of 2 tests
- AgentsCarrying out multi-step tasks on its own10Gemini 3.1 Pro1 of 2 tests · 1 tie
- Long documentsFinding answers in very long texts10Gemini 3.1 Pro1 of 1 test
- Following instructionsDoing exactly what it is asked10Gemini 3.1 Pro1 of 1 test
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 4.1 Fast costs 95% less for the same work.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Gemini 3.1 Pro pulls ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+29.8points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+29.6points ahead
- Very hard expert questions across many subjectsHumanity's Last Exam+27.7points ahead
Where Grok 4.1 Fast pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 28 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGemini 3.1 Pro
- Terminal-Bench HardGemini 3.1 Pro by 29.653.824.2+29.6
- LMArena · WebDevGemini 3.1 Pro by 206 rating points14461240+206 rating
- SciCodeGemini 3.1 Pro by 14.558.744.2+14.5
AgentsGemini 3.1 Pro
- AA IT-Bench SREGemini 3.1 Pro by 12.430.317.9+12.4
- GDPValtie14.714.1tie
ReasoningGemini 3.1 Pro
- Humanity's Last ExamGemini 3.1 Pro by 27.74719.3+27.7
- SimpleBenchGemini 3.1 Pro by 23.679.656+23.6
- CritPtGemini 3.1 Pro by 14.817.72.9+14.8
- GPQA DiamondGemini 3.1 Pro by 8.894.185.3+8.8
FactsGemini 3.1 Pro
- AA-Omniscience · AccuracyGemini 3.1 Pro by 29.854.925.1+29.8
- AA-Omniscience · Non-hallucinationGemini 3.1 Pro by 22.549.126.6+22.5
- Vectara HHEM hallucination ratelower is betterGemini 3.1 Pro by 8.810.419.2+8.8
Images and chartsGemini 3.1 Pro
- MMMU-ProGemini 3.1 Pro by 19.182.463.3+19.1
- LMArena · VisionGemini 3.1 Pro by 95 rating points12961201+95 rating
MathGemini 3.1 Pro
- HMMT Feb. 2026Gemini 3.1 Pro by 8.394.786.4+8.3
- AIME 2026Gemini 3.1 Pro by 4.198.394.2+4.1
Following instructionsGemini 3.1 Pro
- IFBenchGemini 3.1 Pro by 24.477.152.7+24.4
Other results10 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-OmniscienceGemini 3.1 Pro by 61.831.9-29.9+61.8
- Artificial Analysis Coding IndexGemini 3.1 Pro by 49.368.819.5+49.3
- AA Agentic IndexGrok 4.1 Fast by 22.610.332.9+22.6
- matharena_visual_math_overallGemini 3.1 Pro by 20.489.469+20.4
- AA IntelligenceGemini 3.1 Pro by 9.329.720.4+9.3
- vectara_factual_consistencyGemini 3.1 Pro by 8.889.680.8+8.8
- τ²-Bench Telecom (AA run)Gemini 3.1 Pro by 2.395.693.3+2.3
- HMMT Nov. 2025Gemini 3.1 Pro by 1.594.893.3+1.5
- vectara_avg_summary_lengthtie107.799.5tie
- vectara_answer_ratetie99.499.7tie
Questions people ask
Which is better, Gemini 3.1 Pro or Grok 4.1 Fast?
Gemini 3.1 Pro wins all eight areas we test: coding, agents, reasoning, facts, images and charts, math, long documents and following instructions. Grok 4.1 Fast wins none, but costs 95% less.
Which is better for coding?
Gemini 3.1 Pro. It wins 3 of the 3 coding tests both models report; Grok 4.1 Fast wins none.
Which is cheaper?
Gemini 3.1 Pro costs $2.00 per million input tokens and $12.00 per million output tokens; Grok 4.1 Fast costs $0.20 and $0.50. That makes Grok 4.1 Fast about 95% cheaper for the same work.
How do you compare the two?
We use the 28 benchmark tests both models have published scores on. The verdict counts the 18 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 10 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.