Gemini 3.1 Pro Preview vs Mercury 2
Updated October 21, 2026. 42 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 42 shared
Decision reading
Pick Gemini 3.1 Pro Preview for coding: it scores 35.3 on the Vibe Coding Index against 0.0 for Mercury 2.
Pick Mercury 2 when output tokens cost 16.0x less.
Model AGemini 3.1 Pro PreviewGoogle35.3/1001 independent benchmark$0.99 per solved taskModel BMercury 2Inception0.0/1001 independent benchmarkNo cost per solved task
- Shared results
- 42
- Gemini 3.1 Pro Preview only
- 89
- Mercury 2 only
- 0
- Like-for-like categories
- 7 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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, four public coding benchmarks
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview scores 35.3 against 0.0.
One benchmark behind each score
Intelligence
AA Intelligence Index
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 29.7 against 10.8.
Same board, both measured
Agentic work
AA Agentic Index
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 8.2 against 1.6.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only Gemini 3.1 Pro Preview has a GPQA Diamond result, 95.5%.
Directional only
Math
AIME
No call
Only Gemini 3.1 Pro Preview has a AIME result, 98.1%.
Directional only
Knowledge
MMLU Pro
No call
Only Gemini 3.1 Pro Preview has a MMLU Pro result, 91.0%.
Directional only
Web design
Design Arena: websites
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 1234 against 1036.
Same board, both measured
Long documents
Listed context window
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview takes 1.05M tokens against 128K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mercury 2
Gemini 3.1 Pro Preview $0.0080, Mercury 2 $0.0006 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3.1 Pro Preview has the number, $0.99.
Directional only
At a glance
- Coding index
- Gemini 3.1 Pro Preview 35.3 from 1 benchmark, Mercury 2 0.0 from 1 benchmark.
- Widest category
- Web design, 29.3 points apart on average over 8 shared benchmarks.
- Widest single gap
- LMArena WebDev: HTML: Gemini 3.1 Pro Preview 1490 against Mercury 2 1199, 48.4 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Pro Preview $12.00 against Mercury 2 $0.75 per million output tokens, 16.0x apart.
- Context window
- Gemini 3.1 Pro Preview takes 1.05M tokens, Mercury 2 128K.
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 | Mercury 2 | Ties |
|---|---|---|---|---|
| Coding | 10 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 2 | 0 | ||
| Reasoning | 5 | 0 | ||
| Knowledge | 3 | 0 | ||
| Web design | 8 | 0 | ||
| General | 13 | 0 | ||
| All shared boards | 42 | 0 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index100
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| LMArena WebDev | 1447 | 1171 | Gemini 3.1 Pro Preview |
| AA Coding Index | 68.8 | 31.1 | Gemini 3.1 Pro Preview |
| LiveCodeBench (Vals AI) | 88.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| 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 |
| SciCode | 58.7% | 37.7% | Gemini 3.1 Pro Preview |
| Terminal-Bench Hard (Artificial Analysis run) | 53.8% | 26.5% | Gemini 3.1 Pro Preview |
| Terminal-Bench | 80.2% | Not measured | Only Gemini 3.1 Pro Preview measured |
| GSO-Bench | 22.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| WeirdML | 72.1% | 43.2% | Gemini 3.1 Pro Preview |
| MirrorCode | 8.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | 1160.6 | 785.6 | Gemini 3.1 Pro Preview |
| LMArena Text: coding | 1484 | 1390 | Gemini 3.1 Pro Preview |
| LMArena Text: software and IT | 1487 | 1385 | Gemini 3.1 Pro Preview |
| LMArena WebDev: React | 1438 | 1160 | Gemini 3.1 Pro Preview |
| LMArena WebDev: HTML | 1490 | 1199 | Gemini 3.1 Pro Preview |
| LMArena WebDev: from an image | 1481 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 15 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.7 | 10.8 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| AA Agentic Index | 8.2 | 1.6 | Gemini 3.1 Pro Preview |
| 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 | 1055 | 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 | 1114 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: HTML slides | 1153 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: PowerPoint slides | 1064 | 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% | 70.8% | 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 |
| Neither model has a result on the other 15 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| GPQA Diamond | 95.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MysteryMechanism (Vals AI) | 20.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MMMU Pro (Vals AI) | 88.2% | Not measured | Only Gemini 3.1 Pro Preview measured |
| GPQA Diamond (Artificial Analysis run) | 94.1% | 77.0% | Gemini 3.1 Pro Preview |
| Humanity's Last Exam (Artificial Analysis run) | 47.0% | 17.1% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Epoch AI run) | 94.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ARC-AGI | 98.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ARC-AGI-2 | 77.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SimpleBench | 79.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | 51.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Mystery game puzzles | 34.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| EBR-bench | 14.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts | 1485 | 1362 | Gemini 3.1 Pro Preview |
| LMArena Text: expert | 1483 | 1358 | Gemini 3.1 Pro Preview |
| LMArena Text: hard prompts in English | 1480 | 1374 | Gemini 3.1 Pro Preview |
| LMArena Vision: diagrams | 1311 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: homework | 1316 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 4 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| AIME | 98.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| OTIS Mock AIME | 95.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| FrontierMath, tiers 1 to 3 | 59.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| FrontierMath, tier 4 | 26.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ProofBench | 26.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: math | 1486 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: mathematical work | 1478 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| MMLU Pro | 91.0% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LegalBench (Vals AI) | 87.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CaseLaw (Vals AI) | 64.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CorpFin (Vals AI) | 64.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| TaxEval (Vals AI) | 72.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MortgageTax (Vals AI) | 69.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedQA (Vals AI) | 96.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedCode (Vals AI) | 59.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SimpleQA Verified | 73.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: science | 1497 | 1343 | Gemini 3.1 Pro Preview |
| LMArena Text: medicine and healthcare | 1486 | 1363 | Gemini 3.1 Pro Preview |
| LMArena Text: legal and government | 1487 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: business and finance | 1459 | 1349 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| Design Arena: websites | 1234 | 1036 | Gemini 3.1 Pro Preview |
| Design Arena: UI components | 1226 | 998 | Gemini 3.1 Pro Preview |
| Design Arena: game dev | 1203 | 985 | Gemini 3.1 Pro Preview |
| Design Arena: data viz | 1209 | 1009 | Gemini 3.1 Pro Preview |
| Design Arena: 3D | 1234 | 982 | Gemini 3.1 Pro Preview |
| Design Arena: all code categories | 1231 | 1022 | Gemini 3.1 Pro Preview |
| Design Arena: SVG | 1285 | 998 | Gemini 3.1 Pro Preview |
| Design Arena: ASCII art | 1270 | 990 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index130
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| SAGE (Vals AI) | 48.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedScribe (Vals AI) | 76.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vals Multimodal Index | 56.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| IFBench | 77.1% | 69.8% | Gemini 3.1 Pro Preview |
| Long context reasoning (AA-LCR) | 82.0% | 43.7% | Gemini 3.1 Pro Preview |
| DTBench | 97.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMCA | 53.8% | Not measured | Only Gemini 3.1 Pro Preview 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 | 1354 | Gemini 3.1 Pro Preview |
| LMArena Text: instruction following | 1466 | 1328 | Gemini 3.1 Pro Preview |
| LMArena Text: creative writing | 1482 | 1286 | Gemini 3.1 Pro Preview |
| LMArena Vision | 1296 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: English | 1478 | 1378 | Gemini 3.1 Pro Preview |
| LMArena Text: non-English | 1476 | 1330 | Gemini 3.1 Pro Preview |
| LMArena Text: Chinese | 1527 | 1414 | Gemini 3.1 Pro Preview |
| LMArena Text: German | 1490 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Japanese | 1491 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Korean | 1455 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: French | 1487 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Spanish | 1481 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Russian | 1497 | 1304 | Gemini 3.1 Pro Preview |
| LMArena Text: Polish | 1498 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: multi-turn | 1487 | 1357 | Gemini 3.1 Pro Preview |
| LMArena Text: longer queries | 1482 | 1329 | Gemini 3.1 Pro Preview |
| LMArena Text: writing and language | 1481 | 1300 | Gemini 3.1 Pro Preview |
| LMArena Text: entertainment and media | 1465 | 1314 | Gemini 3.1 Pro Preview |
| LMArena Vision: English | 1287 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: Chinese | 1364 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: reading text | 1304 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: humor | 1322 | Not measured | Only Gemini 3.1 Pro Preview measured |
| 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 8 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 | 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
Gemini 3.1 Pro Preview$0.0080Fits in one request
Mercury 2$0.0006Fits in one request
Mercury 2 costs less
Repository review
50K input + 3K output tokens
Gemini 3.1 Pro Preview$0.136Fits in one request
Mercury 2$0.015Fits in one request
Mercury 2 costs less
Agent loop
200K input + 10K output tokens
Gemini 3.1 Pro Preview$0.520Fits in one request
Mercury 2$0.058Exceeds the context window
Mercury 2 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 | Inception Mercury 2 |
|---|---|---|
| Maker | Inception | |
| Weights | No public weights listed | No public weights listed |
| Released | February 19, 2026 | March 4, 2026 |
| Context window | 1.05M | 128K |
| Input $/Mtok | $2.00 | $0.25 |
| Output $/Mtok | $12.00 | $0.75 |
| Coding index | 35.3 | 0.0 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | $0.99 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Pro Preview better than Mercury 2 for coding?
Pick Gemini 3.1 Pro Preview for coding: it scores 35.3 on the Vibe Coding Index against 0.0 for Mercury 2. Pick Mercury 2 when output tokens cost 16.0x less.
Which is cheaper, Gemini 3.1 Pro Preview or Mercury 2?
Gemini 3.1 Pro Preview costs $2.00 per million input tokens and $12.00 per million output tokens; Mercury 2 costs $0.25 and $0.75. Cost per solved task is known for Gemini 3.1 Pro Preview only.
Which has the bigger context window, Gemini 3.1 Pro Preview or Mercury 2?
Gemini 3.1 Pro Preview, with 1.05M tokens against 128K.
How many benchmarks is the Gemini 3.1 Pro Preview vs Mercury 2 comparison based on?
42 benchmarks have a result for both models as of October 21, 2026. Gemini 3.1 Pro Preview's coding index rests on 1 independent benchmark and Mercury 2's on 1. Where only one model has a result, the page says so instead of naming a winner.