Gemini 3.1 Pro Preview vs GPT-5 Nano
Gemini 3.1 Pro Preview leads GPT-5 Nano on the Artificial Analysis Intelligence Index, 29.7 to 13.0, and GPT-5 Nano costs 30.0x less per output token ($0.40 vs $12.00 per million). Updated October 22, 2026; 74 benchmarks have a result for both.
Gemini 3.1 Pro Preview or GPT-5 Nano: which to pick
Only Gemini 3.1 Pro Preview has a coding score, 32.3 on the Vibe Coding Index; GPT-5 Nano has none, so the two cannot be ranked on coding.
Pick GPT-5 Nano for output tokens 30.0x cheaper ($0.40 vs $12.00 per million) and a lower cost per solved task ($0.109 against $0.99).
- Shared results
- 74
- Gemini 3.1 Pro Preview only
- 59
- GPT-5 Nano only
- 13
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Gemini 3.1 Pro Preview has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 29.7 against 13.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 3.1 Pro Preview has a AA Agentic Index result, 8.2.
Directional only
Reasoning
GPQA Diamond
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 95.5% against 63.4%.
Same board, both measured
Math
AIME
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 98.1% against 81.2%.
Same board, both measured
Knowledge
MMLU Pro
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 91.0% against 76.1%.
Same board, both measured
Web design
Design Arena: websites
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 1233 against 1101.
Same board, both measured
Long documents
Listed context window
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview takes 1.05M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5 Nano
Gemini 3.1 Pro Preview $0.0080, GPT-5 Nano $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GPT-5 Nano
Gemini 3.1 Pro Preview $0.99, GPT-5 Nano $0.109.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3.1 Pro Preview 32.3 from 4 benchmarks, GPT-5 Nano not benchmarked.
- Widest category
- Agentic work, 59.1 points apart on average over 1 shared benchmark.
- Widest single gap
- ARC-AGI: Gemini 3.1 Pro Preview 98.0% against GPT-5 Nano 20.7%, 77.3 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Pro Preview $12.00 against GPT-5 Nano $0.40 per million output tokens, 30.0x apart.
- Context window
- Gemini 3.1 Pro Preview takes 1.05M tokens, GPT-5 Nano 400K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Gemini 3.1 Pro Preview | Bars | GPT-5 Nano | Ties |
|---|---|---|---|---|
| Coding | 6 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 14 | 0 | ||
| Math | 7 | 0 | ||
| Knowledge | 12 | 0 | ||
| Web design | 6 | 0 | ||
| General | 27 | 0 | ||
| All shared boards | 74 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index60
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| SWE-bench Verified | Not measured | 34.8% | Only GPT-5 Nano measured |
| LMArena WebDev | 1447 | Not measured | Only Gemini 3.1 Pro Preview measured |
| AA Coding Index | 68.8 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LiveCodeBench (Vals AI) | 88.5% | 70.2% | Gemini 3.1 Pro Preview |
| SWE-bench Verified (Vals AI) | 78.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 4 (Vals AI) | 2.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vibe Code Bench (Vals AI) | 32.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Code migration (Vals AI) | 17.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| IOI (Vals AI) | 51.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 2.1 (Vals AI) | 70.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vibe Code Bench 1-100 (Vals AI) | 6.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 78.9% | Only GPT-5 Nano measured |
| SciCode | 58.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench Hard (Artificial Analysis run) | 53.8% | 17.4% | Gemini 3.1 Pro Preview |
| Terminal-Bench | 80.2% | 21.8% | Gemini 3.1 Pro Preview |
| GSO-Bench | 22.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| WeirdML | 72.1% | 38.1% | Gemini 3.1 Pro Preview |
| MirrorCode | 8.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | 1160.6 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: coding | 1484 | 1351 | Gemini 3.1 Pro Preview |
| LMArena Text: software and IT | 1487 | 1345 | Gemini 3.1 Pro Preview |
| LMArena WebDev: React | 1438 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: HTML | 1490 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: from an image | 1481 | Not measured | Only Gemini 3.1 Pro Preview measured |
| SciCode | 14.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 13 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.7 | 13.0 | Gemini 3.1 Pro Preview |
| Epoch Capabilities Index | Not measured | 139.2 | Only GPT-5 Nano measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| AA Agentic Index | 8.2 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building web apps | 1125 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building full-stack apps | 1068 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building mobile apps | 1094 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Android apps | 1049 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Godot games | 1236 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building games | 1113 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: HTML slides | 1103 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: PowerPoint slides | 1041 | Not measured | Only Gemini 3.1 Pro Preview measured |
| SREBench (Vals AI) | 0.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Finance Agent (Vals AI) | 43.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Tax Agent Bench (Vals AI) | 9.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Legal Research Bench (Vals AI) | 20.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Excel Modeling Benchmark (Vals AI) | 52.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| BioMysteryBench (Vals AI) | 60.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench-Science (Vals AI) | 1.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vals Science Index | 27.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| τ²-Bench Telecom | 95.6% | 36.5% | Gemini 3.1 Pro Preview |
| APEX-Agents | 35.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| METR time horizons | 77.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| BALROG | 57.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| DeepResearch Bench | 47.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| PostTrainBench | 22.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vending-Bench 2 | $911 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Berkeley Function Calling Leaderboard (BFCL) | Not measured | 51.4% | Only GPT-5 Nano measured |
| Neither model has a result on the other 16 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index140
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| GPQA Diamond | 95.5% | 63.4% | Gemini 3.1 Pro Preview |
| MysteryMechanism (Vals AI) | 20.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MMMU Pro (Vals AI) | 88.2% | 70.9% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Artificial Analysis run) | 94.1% | 67.6% | Gemini 3.1 Pro Preview |
| Humanity's Last Exam (Artificial Analysis run) | 47.0% | 9.5% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Epoch AI run) | 94.4% | 69.4% | Gemini 3.1 Pro Preview |
| ARC-AGI | 98.0% | 20.7% | Gemini 3.1 Pro Preview |
| ARC-AGI-2 | 77.1% | 2.6% | Gemini 3.1 Pro Preview |
| SimpleBench | 79.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | 51.0% | 22.0% | Gemini 3.1 Pro Preview |
| Mystery game puzzles | 34.0% | 9.0% | Gemini 3.1 Pro Preview |
| EBR-bench | 14.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| VPCT | Not measured | 37.2% | Only GPT-5 Nano measured |
| LMArena Text: hard prompts | 1485 | 1328 | Gemini 3.1 Pro Preview |
| LMArena Text: expert | 1483 | 1321 | Gemini 3.1 Pro Preview |
| LMArena Text: hard prompts in English | 1480 | 1338 | Gemini 3.1 Pro Preview |
| LMArena Vision: diagrams | 1311 | 1141 | Gemini 3.1 Pro Preview |
| LMArena Vision: homework | 1316 | 1157 | Gemini 3.1 Pro Preview |
| Kagi LLM Benchmark | Not measured | 62.2% | Only GPT-5 Nano measured |
| Neither model has a result on the other 3 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index70
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| AIME | 98.1% | 81.2% | Gemini 3.1 Pro Preview |
| MATH 500 (Vals AI) | Not measured | 93.8% | Only GPT-5 Nano measured |
| MGSM (Vals AI) | Not measured | 89.3% | Only GPT-5 Nano measured |
| AA Math Index | Not measured | 83.7 | Only GPT-5 Nano measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 83.7% | Only GPT-5 Nano measured |
| OTIS Mock AIME | 95.6% | 81.1% | Gemini 3.1 Pro Preview |
| FrontierMath, tiers 1 to 3 | 59.6% | 20.0% | Gemini 3.1 Pro Preview |
| FrontierMath, tier 4 | 26.8% | 2.4% | Gemini 3.1 Pro Preview |
| ProofBench | 26.0% | 12.0% | Gemini 3.1 Pro Preview |
| MATH level 5 | Not measured | 95.2% | Only GPT-5 Nano measured |
| LMArena Text: math | 1486 | 1317 | Gemini 3.1 Pro Preview |
| LMArena Text: mathematical work | 1478 | 1326 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 1 board here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index120
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| MMLU Pro | 91.0% | 76.1% | Gemini 3.1 Pro Preview |
| LegalBench (Vals AI) | 87.4% | 50.1% | Gemini 3.1 Pro Preview |
| CaseLaw (Vals AI) | 64.8% | 52.6% | Gemini 3.1 Pro Preview |
| CorpFin (Vals AI) | 64.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| TaxEval (Vals AI) | 72.9% | 67.4% | Gemini 3.1 Pro Preview |
| MortgageTax (Vals AI) | 69.4% | 53.6% | Gemini 3.1 Pro Preview |
| MedQA (Vals AI) | 96.4% | 93.3% | Gemini 3.1 Pro Preview |
| MedCode (Vals AI) | 59.1% | 30.4% | Gemini 3.1 Pro Preview |
| MMLU Pro (Artificial Analysis run) | Not measured | 78.0% | Only GPT-5 Nano measured |
| SimpleQA Verified | 73.5% | 11.7% | Gemini 3.1 Pro Preview |
| LMArena Text: science | 1497 | 1318 | Gemini 3.1 Pro Preview |
| LMArena Text: medicine and healthcare | 1486 | 1335 | Gemini 3.1 Pro Preview |
| LMArena Text: legal and government | 1487 | 1298 | Gemini 3.1 Pro Preview |
| LMArena Text: business and finance | 1459 | 1311 | Gemini 3.1 Pro Preview |
| FACTS Benchmark Suite | 67.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 3 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| Design Arena: websites | 1233 | 1101 | Gemini 3.1 Pro Preview |
| Design Arena: UI components | 1224 | 1064 | Gemini 3.1 Pro Preview |
| Design Arena: game dev | 1202 | 1044 | Gemini 3.1 Pro Preview |
| Design Arena: data viz | 1209 | 1056 | Gemini 3.1 Pro Preview |
| Design Arena: 3D | 1234 | 965 | Gemini 3.1 Pro Preview |
| Design Arena: all code categories | 1231 | 1084 | Gemini 3.1 Pro Preview |
| Design Arena: SVG | 1285 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: ASCII art | 1270 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index270
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SAGE (Vals AI) | 48.7% | 30.4% | Gemini 3.1 Pro Preview |
| MedScribe (Vals AI) | 76.1% | 72.9% | Gemini 3.1 Pro Preview |
| Vals Multimodal Index | 56.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| IFBench | 77.1% | 67.6% | Gemini 3.1 Pro Preview |
| Long context reasoning (AA-LCR) | 82.0% | 45.0% | Gemini 3.1 Pro Preview |
| DTBench | 97.1% | 62.7% | Gemini 3.1 Pro Preview |
| LMCA | 53.8% | 7.9% | Gemini 3.1 Pro Preview |
| Fiction.LiveBench | Not measured | 44.4% | Only GPT-5 Nano measured |
| CL-bench | 20.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Furniture assembly | 26.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ExploitBench | 26.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CL-bench Life | 16.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text | 1480 | 1320 | Gemini 3.1 Pro Preview |
| LMArena Text: instruction following | 1466 | 1306 | Gemini 3.1 Pro Preview |
| LMArena Text: creative writing | 1482 | 1249 | Gemini 3.1 Pro Preview |
| LMArena Vision | 1296 | 1159 | Gemini 3.1 Pro Preview |
| LMArena Text: English | 1478 | 1321 | Gemini 3.1 Pro Preview |
| LMArena Text: non-English | 1476 | 1313 | Gemini 3.1 Pro Preview |
| LMArena Text: Chinese | 1527 | 1356 | Gemini 3.1 Pro Preview |
| LMArena Text: German | 1490 | 1327 | Gemini 3.1 Pro Preview |
| LMArena Text: Japanese | 1491 | 1227 | Gemini 3.1 Pro Preview |
| LMArena Text: Korean | 1455 | 1269 | Gemini 3.1 Pro Preview |
| LMArena Text: French | 1487 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Spanish | 1481 | 1360 | Gemini 3.1 Pro Preview |
| LMArena Text: Russian | 1497 | 1296 | Gemini 3.1 Pro Preview |
| LMArena Text: Polish | 1498 | 1314 | Gemini 3.1 Pro Preview |
| LMArena Text: multi-turn | 1487 | 1311 | Gemini 3.1 Pro Preview |
| LMArena Text: longer queries | 1482 | 1312 | Gemini 3.1 Pro Preview |
| LMArena Text: writing and language | 1481 | 1283 | Gemini 3.1 Pro Preview |
| LMArena Text: entertainment and media | 1465 | 1268 | Gemini 3.1 Pro Preview |
| LMArena Vision: English | 1287 | 1170 | Gemini 3.1 Pro Preview |
| LMArena Vision: Chinese | 1364 | 1176 | Gemini 3.1 Pro Preview |
| LMArena Vision: reading text | 1304 | 1152 | Gemini 3.1 Pro Preview |
| LMArena Vision: humor | 1322 | 1110 | Gemini 3.1 Pro Preview |
| LMArena Vision: captioning | 1345 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: recognizing things | 1330 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: creative writing | 1324 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Document | 1444 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 7 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.1 Pro Preview | GPT-5 Nano | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
GPT-5 Nano costs less
Repository review
50K input + 3K output tokens
GPT-5 Nano costs less
Agent loop
200K input + 10K output tokens
GPT-5 Nano costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Google Gemini 3.1 Pro Preview | OpenAI GPT-5 Nano |
|---|---|---|
| Maker | OpenAI | |
| Weights | No public weights listed | No public weights listed |
| Released | February 19, 2026 | August 7, 2025 |
| Context window | 1.05M | 400K |
| Input $/Mtok | $2.00 | $0.05 |
| Output $/Mtok | $12.00 | $0.40 |
| Coding index | 32.3 | Not benchmarked |
| Independent measurements behind it | 4 | 0 |
| Cost per solved task | $0.99 | $0.109 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Pro Preview better than GPT-5 Nano for coding?
Only Gemini 3.1 Pro Preview has a coding score, 32.3 on the Vibe Coding Index; GPT-5 Nano has none, so the two cannot be ranked on coding. Pick GPT-5 Nano for output tokens 30.0x cheaper ($0.40 vs $12.00 per million) and a lower cost per solved task ($0.109 against $0.99).
Which is cheaper, Gemini 3.1 Pro Preview or GPT-5 Nano?
Gemini 3.1 Pro Preview costs $2.00 per million input tokens and $12.00 per million output tokens; GPT-5 Nano costs $0.05 and $0.40. Per solved SWE-bench Verified task, Gemini 3.1 Pro Preview costs $0.99 and GPT-5 Nano $0.109.
Which has the bigger context window, Gemini 3.1 Pro Preview or GPT-5 Nano?
Gemini 3.1 Pro Preview, with 1.05M tokens against 400K.
How many benchmarks is the Gemini 3.1 Pro Preview vs GPT-5 Nano comparison based on?
74 benchmarks have a result for both models as of October 22, 2026. Gemini 3.1 Pro Preview's coding index rests on 4 independent benchmarks and GPT-5 Nano's on 0. Where only one model has a result, the page says so instead of naming a winner.