Gemini 3.1 Pro Preview vs Gemini 3.5 Flash Lite
Updated October 21, 2026. 81 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Gemini 3.1 Pro Preview and Gemini 3.5 Flash Lite are level for coding, 35.3 against 33.6 on the Vibe Coding Index, so price and context decide.
Pick Gemini 3.5 Flash Lite when output tokens cost 4.8x less, or when a solved task costs $0.41 against $0.99. Pick Gemini 3.1 Pro Preview when what matters is LMArena WebDev or AA Coding Index, where it leads.
- Shared results
- 81
- Gemini 3.1 Pro Preview only
- 50
- Gemini 3.5 Flash Lite only
- 2
- 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
No call
Level: 35.3 against 33.6, inside 2 points.
One benchmark behind each score
Intelligence
AA Intelligence Index
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 29.7 against 22.2.
Same board, both measured
Agentic work
AA Agentic Index
Gemini 3.5 Flash Lite
Gemini 3.5 Flash Lite leads, 14.3 against 8.2.
Same board, both measured
Reasoning
GPQA Diamond
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 95.5% against 83.8%.
Same board, both measured
Math
AIME
No call
Only Gemini 3.1 Pro Preview has a AIME result, 98.1%.
Directional only
Knowledge
MMLU Pro
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview leads, 91.0% against 85.8%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Gemini 3.1 Pro Preview has a Design Arena: websites result, 1234.
Directional only
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 3.5 Flash Lite
Gemini 3.1 Pro Preview $0.0080, Gemini 3.5 Flash Lite $0.0015 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Gemini 3.5 Flash Lite
Gemini 3.1 Pro Preview $0.99, Gemini 3.5 Flash Lite $0.41.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3.1 Pro Preview 35.3 from 1 benchmark, Gemini 3.5 Flash Lite 33.6 from 1 benchmark.
- Widest category
- Math, 19.0 points apart on average over 6 shared benchmarks.
- Widest single gap
- ARC-AGI-2: Gemini 3.1 Pro Preview 77.1% against Gemini 3.5 Flash Lite 10.3%, 66.8 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Pro Preview $12.00 against Gemini 3.5 Flash Lite $2.50 per million output tokens, 4.8x apart.
- Context window
- Both take 1.05M tokens.
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 | Gemini 3.5 Flash Lite | Ties |
|---|---|---|---|---|
| Coding | 13 | 1 | 1 tie | |
| Intelligence | 1 | 0 | ||
| Agentic work | 4 | 2 | ||
| Reasoning | 14 | 0 | ||
| Math | 6 | 0 | ||
| Knowledge | 10 | 0 | ||
| General | 29 | 0 | ||
| All shared boards | 77 | 3 | 1 tie |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index131
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| LMArena WebDev | 1447 | 1435 | Gemini 3.1 Pro Preview |
| AA Coding Index | 68.8 | 49.3 | Gemini 3.1 Pro Preview |
| LiveCodeBench (Vals AI) | 88.5% | 79.0% | Gemini 3.1 Pro Preview |
| SWE-bench Verified (Vals AI) | 78.8% | 75.0% | Gemini 3.1 Pro Preview |
| Terminal-Bench 4 (Vals AI) | 2.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Vibe Code Bench (Vals AI) | 32.0% | 37.2% | Gemini 3.5 Flash Lite |
| Code migration (Vals AI) | 17.3% | 6.2% | Gemini 3.1 Pro Preview |
| ProgramBench (Vals AI) | 0.0% | 0.0% | Tie |
| IOI (Vals AI) | 51.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 2.1 (Vals AI) | 70.8% | 50.2% | Gemini 3.1 Pro Preview |
| Vibe Code Bench 1-100 (Vals AI) | 6.7% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CyberBench (Vals AI) | Not measured | 59.1% | Only Gemini 3.5 Flash Lite measured |
| SciCode | 58.7% | 41.3% | Gemini 3.1 Pro Preview |
| Terminal-Bench Hard (Artificial Analysis run) | 53.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| 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% | 39.0% | Gemini 3.1 Pro Preview |
| MirrorCode | 8.9% | Not measured | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | 1160.6 | 765.3 | Gemini 3.1 Pro Preview |
| LMArena Text: coding | 1484 | 1453 | Gemini 3.1 Pro Preview |
| LMArena Text: software and IT | 1487 | 1451 | Gemini 3.1 Pro Preview |
| LMArena WebDev: React | 1438 | 1408 | Gemini 3.1 Pro Preview |
| LMArena WebDev: HTML | 1490 | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: from an image | 1481 | 1448 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 14 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| AA Intelligence Index | 29.7 | 22.2 | Gemini 3.1 Pro Preview |
| Epoch Capabilities Index | Not measured | 144.9 | Only Gemini 3.5 Flash Lite measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index42
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| AA Agentic Index | 8.2 | 14.3 | Gemini 3.5 Flash Lite |
| 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% | 47.4% | Gemini 3.5 Flash Lite |
| Tax Agent Bench (Vals AI) | 9.3% | 7.2% | Gemini 3.1 Pro Preview |
| Legal Research Bench (Vals AI) | 20.7% | 13.9% | Gemini 3.1 Pro Preview |
| Excel Modeling Benchmark (Vals AI) | 52.6% | 43.2% | Gemini 3.1 Pro Preview |
| 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% | Not measured | Only Gemini 3.1 Pro Preview measured |
| APEX-Agents | 35.1% | 29.3% | Gemini 3.1 Pro Preview |
| 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 index140
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| GPQA Diamond | 95.5% | 83.8% | 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% | 83.6% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Artificial Analysis run) | 94.1% | 83.8% | Gemini 3.1 Pro Preview |
| Humanity's Last Exam (Artificial Analysis run) | 47.0% | 18.8% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Epoch AI run) | 94.4% | 83.3% | Gemini 3.1 Pro Preview |
| ARC-AGI | 98.0% | 53.5% | Gemini 3.1 Pro Preview |
| ARC-AGI-2 | 77.1% | 10.3% | Gemini 3.1 Pro Preview |
| SimpleBench | 79.6% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | 51.0% | 21.0% | Gemini 3.1 Pro Preview |
| Mystery game puzzles | 34.0% | 19.0% | Gemini 3.1 Pro Preview |
| EBR-bench | 14.3% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts | 1485 | 1441 | Gemini 3.1 Pro Preview |
| LMArena Text: expert | 1483 | 1434 | Gemini 3.1 Pro Preview |
| LMArena Text: hard prompts in English | 1480 | 1440 | Gemini 3.1 Pro Preview |
| LMArena Vision: diagrams | 1311 | 1284 | Gemini 3.1 Pro Preview |
| LMArena Vision: homework | 1316 | 1291 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| AIME | 98.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| OTIS Mock AIME | 95.6% | 71.1% | Gemini 3.1 Pro Preview |
| FrontierMath, tiers 1 to 3 | 59.6% | 26.0% | Gemini 3.1 Pro Preview |
| FrontierMath, tier 4 | 26.8% | 0.0% | Gemini 3.1 Pro Preview |
| ProofBench | 26.0% | 13.0% | Gemini 3.1 Pro Preview |
| LMArena Text: math | 1486 | 1434 | Gemini 3.1 Pro Preview |
| LMArena Text: mathematical work | 1478 | 1433 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 6 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index100
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| MMLU Pro | 91.0% | 85.8% | Gemini 3.1 Pro Preview |
| LegalBench (Vals AI) | 87.4% | 84.1% | Gemini 3.1 Pro Preview |
| CaseLaw (Vals AI) | 64.8% | Not measured | Only Gemini 3.1 Pro Preview measured |
| CorpFin (Vals AI) | 64.5% | 60.7% | Gemini 3.1 Pro Preview |
| TaxEval (Vals AI) | 72.9% | 72.6% | Gemini 3.1 Pro Preview |
| MortgageTax (Vals AI) | 69.4% | 68.7% | Gemini 3.1 Pro Preview |
| MedQA (Vals AI) | 96.4% | Not measured | Only Gemini 3.1 Pro Preview measured |
| MedCode (Vals AI) | 59.1% | 43.5% | Gemini 3.1 Pro Preview |
| SimpleQA Verified | 73.5% | Not measured | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: science | 1497 | 1451 | Gemini 3.1 Pro Preview |
| LMArena Text: medicine and healthcare | 1486 | 1438 | Gemini 3.1 Pro Preview |
| LMArena Text: legal and government | 1487 | 1431 | Gemini 3.1 Pro Preview |
| LMArena Text: business and finance | 1459 | 1423 | Gemini 3.1 Pro Preview |
| Neither model has a result on the other 4 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| Design Arena: websites | 1234 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: UI components | 1226 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: game dev | 1203 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: data viz | 1209 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: 3D | 1234 | Not measured | Only Gemini 3.1 Pro Preview measured |
| Design Arena: all code categories | 1231 | Not measured | Only Gemini 3.1 Pro Preview measured |
| 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 index290
| Benchmark | Gemini 3.1 Pro Preview | Gemini 3.5 Flash Lite | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | 53.8% | 51.8% | Gemini 3.1 Pro Preview |
| SAGE (Vals AI) | 48.7% | 47.3% | Gemini 3.1 Pro Preview |
| MedScribe (Vals AI) | 76.1% | 70.9% | Gemini 3.1 Pro Preview |
| Vals Multimodal Index | 56.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| IFBench | 77.1% | Not measured | Only Gemini 3.1 Pro Preview measured |
| Long context reasoning (AA-LCR) | 82.0% | 76.0% | Gemini 3.1 Pro Preview |
| DTBench | 97.1% | 83.5% | Gemini 3.1 Pro Preview |
| LMCA | 53.8% | 37.6% | Gemini 3.1 Pro Preview |
| 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 | 1435 | Gemini 3.1 Pro Preview |
| LMArena Text: instruction following | 1466 | 1419 | Gemini 3.1 Pro Preview |
| LMArena Text: creative writing | 1482 | 1421 | Gemini 3.1 Pro Preview |
| LMArena Vision | 1296 | 1269 | Gemini 3.1 Pro Preview |
| LMArena Text: English | 1478 | 1438 | Gemini 3.1 Pro Preview |
| LMArena Text: non-English | 1476 | 1427 | Gemini 3.1 Pro Preview |
| LMArena Text: Chinese | 1527 | 1468 | Gemini 3.1 Pro Preview |
| LMArena Text: German | 1490 | 1454 | Gemini 3.1 Pro Preview |
| LMArena Text: Japanese | 1491 | 1426 | Gemini 3.1 Pro Preview |
| LMArena Text: Korean | 1455 | 1407 | Gemini 3.1 Pro Preview |
| LMArena Text: French | 1487 | 1451 | Gemini 3.1 Pro Preview |
| LMArena Text: Spanish | 1481 | 1441 | Gemini 3.1 Pro Preview |
| LMArena Text: Russian | 1497 | 1443 | Gemini 3.1 Pro Preview |
| LMArena Text: Polish | 1498 | 1437 | Gemini 3.1 Pro Preview |
| LMArena Text: multi-turn | 1487 | 1445 | Gemini 3.1 Pro Preview |
| LMArena Text: longer queries | 1482 | 1435 | Gemini 3.1 Pro Preview |
| LMArena Text: writing and language | 1481 | 1428 | Gemini 3.1 Pro Preview |
| LMArena Text: entertainment and media | 1465 | 1414 | Gemini 3.1 Pro Preview |
| LMArena Vision: English | 1287 | 1269 | Gemini 3.1 Pro Preview |
| LMArena Vision: Chinese | 1364 | 1311 | Gemini 3.1 Pro Preview |
| LMArena Vision: reading text | 1304 | 1280 | Gemini 3.1 Pro Preview |
| LMArena Vision: humor | 1322 | 1287 | 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 | 1260 | Gemini 3.1 Pro Preview |
| 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 | Gemini 3.5 Flash Lite | 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 3.5 Flash Lite costs less
Repository review
50K input + 3K output tokens
Gemini 3.5 Flash Lite costs less
Agent loop
200K input + 10K output tokens
Gemini 3.5 Flash Lite 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 | Google Gemini 3.5 Flash Lite |
|---|---|---|
| Maker | ||
| Weights | No public weights listed | No public weights listed |
| Released | February 19, 2026 | July 21, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $2.00 | $0.30 |
| Output $/Mtok | $12.00 | $2.50 |
| Coding index | 35.3 | 33.6 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | $0.99 | $0.41 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Pro Preview better than Gemini 3.5 Flash Lite for coding?
Gemini 3.1 Pro Preview and Gemini 3.5 Flash Lite are level for coding, 35.3 against 33.6 on the Vibe Coding Index, so price and context decide. Pick Gemini 3.5 Flash Lite when output tokens cost 4.8x less, or when a solved task costs $0.41 against $0.99. Pick Gemini 3.1 Pro Preview when what matters is LMArena WebDev or AA Coding Index, where it leads.
Which is cheaper, Gemini 3.1 Pro Preview or Gemini 3.5 Flash Lite?
Gemini 3.1 Pro Preview costs $2.00 per million input tokens and $12.00 per million output tokens; Gemini 3.5 Flash Lite costs $0.30 and $2.50. Per solved SWE-bench Verified task, Gemini 3.1 Pro Preview costs $0.99 and Gemini 3.5 Flash Lite $0.41.
Which has the bigger context window, Gemini 3.1 Pro Preview or Gemini 3.5 Flash Lite?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 3.1 Pro Preview vs Gemini 3.5 Flash Lite comparison based on?
81 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 Gemini 3.5 Flash Lite's on 1. Where only one model has a result, the page says so instead of naming a winner.