Compare · ModelsLive · 2 picked · head to head

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash

Side by side · benchmarks, pricing, and signals you can act on.

Winner summary

Gemini 3.1 Pro Preview wins 11 of 19 shared benchmarks. Leads in reasoning · knowledge · math.

Category leads
speed·Gemini 3.5 Flashagentic·Gemini 3.5 Flashreasoning·Gemini 3.1 Pro Previewarena·Gemini 3.5 Flashknowledge·Gemini 3.1 Pro Previewmath·Gemini 3.1 Pro Previewcoding·Gemini 3.5 Flash
Hype vs Reality
Gemini 3.1 Pro Preview
#74 by perf·no signal
QUIET
Gemini 3.5 Flash
#44 by perf·no signal
QUIET
Best value
1.5x better value than Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
8.1 pts/$
$7.00/M
Gemini 3.5 Flash
11.9 pts/$
$5.25/M
Vendor risk
Google DeepMind logo
Google DeepMind
$4.00T·Tier 1
Low risk
Google DeepMind logo
Google DeepMind
$4.00T·Tier 1
Low risk
Head to head
Gemini 3.1 Pro PreviewGemini 3.5 Flash
Artificial Analysis · Agentic Index
Gemini 3.5 Flash leads by +16.1
Artificial Analysis Agentic Index · a composite score measuring how well a model performs in agentic workflows · multi-step tool use, planning, error recovery, and autonomous task completion. Aggregates results from multiple agentic benchmarks including SWE-bench, tool-use tests, and planning evaluations. The canonical single-number metric for "how good is this model as an agent?"
Gemini 3.1 Pro Preview
21.4
Gemini 3.5 Flash
37.5
Artificial Analysis · Coding Index
Gemini 3.5 Flash leads by +1.3
Artificial Analysis Coding Index · a composite score that aggregates performance across multiple coding benchmarks into a single index. Tracks code generation quality, debugging ability, multi-language competence, and real-world software engineering tasks. Used by Artificial Analysis to rank model coding capability in a normalized, comparable format. Useful for developers choosing between models for coding-heavy workloads.
Gemini 3.1 Pro Preview
68.8
Gemini 3.5 Flash
70.1
Artificial Analysis · Quality Index
Gemini 3.5 Flash leads by +3.7
Gemini 3.1 Pro Preview
46.5
Gemini 3.5 Flash
50.2
APEX-Agents
Gemini 3.5 Flash leads by +16.1
APEX-Agents · evaluates AI agents on complex, multi-step tasks requiring planning, tool use, and autonomous decision-making in realistic environments.
Gemini 3.1 Pro Preview
33.5
Gemini 3.5 Flash
49.6
ARC-AGI
Gemini 3.1 Pro Preview leads by +5.5
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
Gemini 3.1 Pro Preview
98.0
Gemini 3.5 Flash
92.5
ARC-AGI-2
Gemini 3.1 Pro Preview leads by +5.0
ARC-AGI-2 · the second iteration of the Abstraction and Reasoning Corpus, testing novel pattern recognition and abstract reasoning without prior training data.
Gemini 3.1 Pro Preview
77.1
Gemini 3.5 Flash
72.1
Chatbot Arena Elo · Coding
Gemini 3.5 Flash leads by +58.6
Gemini 3.1 Pro Preview
1447.0
Gemini 3.5 Flash
1505.5
Chatbot Arena Elo · Overall
Gemini 3.1 Pro Preview leads by +10.2
Gemini 3.1 Pro Preview
1486.4
Gemini 3.5 Flash
1476.3
Chess Puzzles
Gemini 3.1 Pro Preview leads by +5.0
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
Gemini 3.1 Pro Preview
55.0
Gemini 3.5 Flash
50.0
FrontierMath-2025-02-28-Private
Gemini 3.5 Flash leads by +2.1
FrontierMath (Feb 2025) · original research-level math problems created by mathematicians, testing capabilities at the boundary of current AI mathematical reasoning.
Gemini 3.1 Pro Preview
36.9
Gemini 3.5 Flash
39.0
FrontierMath-Tier-4-2025-07-01-Private
Gemini 3.1 Pro Preview leads by +2.1
FrontierMath Tier 4 (Jul 2025) · the most challenging tier of frontier mathematics, containing problems that push the absolute limits of AI mathematical reasoning.
Gemini 3.1 Pro Preview
16.7
Gemini 3.5 Flash
14.6
FrontierMath-Tier-4-v2-Private
Gemini 3.1 Pro Preview
26.8
Gemini 3.5 Flash
26.8
FrontierMath-Tiers-1-3-v2-Private
Gemini 3.5 Flash leads by +3.2
Gemini 3.1 Pro Preview
59.6
Gemini 3.5 Flash
62.8
GPQA diamond
Gemini 3.1 Pro Preview leads by +1.7
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Gemini 3.1 Pro Preview
92.1
Gemini 3.5 Flash
90.4
OTIS Mock AIME 2024-2025
Gemini 3.1 Pro Preview leads by +0.0
OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills.
Gemini 3.1 Pro Preview
95.6
Gemini 3.5 Flash
95.5
SimpleBench
Gemini 3.1 Pro Preview leads by +3.5
SimpleBench · tests fundamental reasoning capabilities with straightforward problems designed to expose gaps in basic logical and spatial thinking.
Gemini 3.1 Pro Preview
75.5
Gemini 3.5 Flash
72.0
SimpleQA Verified
Gemini 3.1 Pro Preview leads by +8.9
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
Gemini 3.1 Pro Preview
77.3
Gemini 3.5 Flash
68.4
SWE-Bench verified
Gemini 3.5 Flash leads by +3.7
SWE-bench Verified · 500 human-validated tasks from 12 real Python repositories (Django, Flask, scikit-learn, sympy, and others). Each task requires the model to produce a git patch that resolves a real GitHub issue and passes the test suite. The verified subset eliminates ambiguous tasks from the original SWE-bench. Claude Mythos Preview leads at 93.9%, crossing 90% for the first time in 2026. Opus 4.6 scores 80.8%. The benchmark remains the most-cited evaluation for code-generation capability.
Gemini 3.1 Pro Preview
75.6
Gemini 3.5 Flash
79.3
WeirdML
Gemini 3.1 Pro Preview leads by +9.5
WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns.
Gemini 3.1 Pro Preview
72.1
Gemini 3.5 Flash
62.6
Full benchmark table
BenchmarkGemini 3.1 Pro PreviewGemini 3.5 Flash
Artificial Analysis · Agentic Index
Artificial Analysis Agentic Index · a composite score measuring how well a model performs in agentic workflows · multi-step tool use, planning, error recovery, and autonomous task completion. Aggregates results from multiple agentic benchmarks including SWE-bench, tool-use tests, and planning evaluations. The canonical single-number metric for "how good is this model as an agent?"
21.437.5
Artificial Analysis · Coding Index
Artificial Analysis Coding Index · a composite score that aggregates performance across multiple coding benchmarks into a single index. Tracks code generation quality, debugging ability, multi-language competence, and real-world software engineering tasks. Used by Artificial Analysis to rank model coding capability in a normalized, comparable format. Useful for developers choosing between models for coding-heavy workloads.
68.870.1
Artificial Analysis · Quality Index
46.550.2
APEX-Agents
APEX-Agents · evaluates AI agents on complex, multi-step tasks requiring planning, tool use, and autonomous decision-making in realistic environments.
33.549.6
ARC-AGI
ARC-AGI · the original Abstraction and Reasoning Corpus, testing whether AI can solve novel visual pattern recognition tasks without memorization.
98.092.5
ARC-AGI-2
ARC-AGI-2 · the second iteration of the Abstraction and Reasoning Corpus, testing novel pattern recognition and abstract reasoning without prior training data.
77.172.1
Chatbot Arena Elo · Coding
1447.01505.5
Chatbot Arena Elo · Overall
1486.41476.3
Chess Puzzles
Chess Puzzles · tests strategic and tactical reasoning by having models solve chess puzzle positions, evaluating lookahead and pattern recognition abilities.
55.050.0
FrontierMath-2025-02-28-Private
FrontierMath (Feb 2025) · original research-level math problems created by mathematicians, testing capabilities at the boundary of current AI mathematical reasoning.
36.939.0
FrontierMath-Tier-4-2025-07-01-Private
FrontierMath Tier 4 (Jul 2025) · the most challenging tier of frontier mathematics, containing problems that push the absolute limits of AI mathematical reasoning.
16.714.6
FrontierMath-Tier-4-v2-Private
26.826.8
FrontierMath-Tiers-1-3-v2-Private
59.662.8
GPQA diamond
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
92.190.4
OTIS Mock AIME 2024-2025
OTIS Mock AIME 2024-2025 · simulated American Invitational Mathematics Examination problems testing advanced problem-solving skills.
95.695.5
SimpleBench
SimpleBench · tests fundamental reasoning capabilities with straightforward problems designed to expose gaps in basic logical and spatial thinking.
75.572.0
SimpleQA Verified
SimpleQA Verified · short factual questions with verified answers, measuring factual accuracy and the tendency to hallucinate or provide incorrect information.
77.368.4
SWE-Bench verified
SWE-bench Verified · 500 human-validated tasks from 12 real Python repositories (Django, Flask, scikit-learn, sympy, and others). Each task requires the model to produce a git patch that resolves a real GitHub issue and passes the test suite. The verified subset eliminates ambiguous tasks from the original SWE-bench. Claude Mythos Preview leads at 93.9%, crossing 90% for the first time in 2026. Opus 4.6 scores 80.8%. The benchmark remains the most-cited evaluation for code-generation capability.
75.679.3
WeirdML
WeirdML · tests models on unusual and adversarial machine learning tasks that require creative problem-solving beyond standard patterns.
72.162.6
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
Google DeepMind logoGemini 3.1 Pro Preview$2.00$12.001.0M tokens (~524 books)$45.00
Google DeepMind logoGemini 3.5 Flash$1.50$9.001.0M tokens (~524 books)$33.75