Gemini 3.1 Flash Lite vs Gemini 3.1 Pro Preview
Gemini 3.1 Flash Lite costs 8.0x less per output token than Gemini 3.1 Pro Preview ($1.50 vs $12.00 per million). Updated October 22, 2026; 14 benchmarks have a result for both.
vs boards won of 14 shared
Gemini 3.1 Flash Lite or Gemini 3.1 Pro Preview: which to pick
Only Gemini 3.1 Pro Preview has a coding score, 32.3 on the Vibe Coding Index; Gemini 3.1 Flash Lite has none, so the two cannot be ranked on coding.
Pick Gemini 3.1 Flash Lite for output tokens 8.0x cheaper ($1.50 vs $12.00 per million) and work measured by IFBench, where it leads.
Model AGemini 3.1 Flash LiteGoogleNot benchmarkedNo coding benchmarkNo cost per solved taskModel BGemini 3.1 Pro PreviewGoogle32.3/1004 independent benchmarks$0.99 per solved task
- Shared results
- 14
- Gemini 3.1 Flash Lite only
- 2
- Gemini 3.1 Pro Preview only
- 119
- Like-for-like categories
- 5 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
No call
Only Gemini 3.1 Pro Preview has a AA Intelligence Index result, 29.7.
Directional only
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
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
No call
Only Gemini 3.1 Pro Preview has a Design Arena: websites result, 1233.
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 3.1 Flash Lite
Gemini 3.1 Flash Lite $0.0010, Gemini 3.1 Pro Preview $0.0080 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 Flash Lite not benchmarked, Gemini 3.1 Pro Preview 32.3 from 4 benchmarks.
- Widest category
- Agentic work, 37.4 points apart on average over 2 shared benchmarks.
- Widest single gap
- τ²-Bench Telecom: Gemini 3.1 Flash Lite 31.3% against Gemini 3.1 Pro Preview 95.6%, 64.3 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.1 Flash Lite $1.50 against Gemini 3.1 Pro Preview $12.00 per million output tokens, 8.0x 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 Flash Lite | Bars | Gemini 3.1 Pro Preview | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Agentic work | 0 | 2 | ||
| Reasoning | 0 | 3 | ||
| Math | 0 | 2 | ||
| General | 1 | 3 | ||
| All shared boards | 1 | 13 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index03
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1447 | Only Gemini 3.1 Pro Preview measured |
| AA Coding Index | Not measured | 68.8 | Only Gemini 3.1 Pro Preview measured |
| LiveCodeBench (Vals AI) | Not measured | 88.5% | Only Gemini 3.1 Pro Preview measured |
| SWE-bench Verified (Vals AI) | Not measured | 78.8% | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 2.5% | Only Gemini 3.1 Pro Preview measured |
| Vibe Code Bench (Vals AI) | Not measured | 32.0% | Only Gemini 3.1 Pro Preview measured |
| Code migration (Vals AI) | Not measured | 17.3% | Only Gemini 3.1 Pro Preview measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Gemini 3.1 Pro Preview measured |
| IOI (Vals AI) | Not measured | 51.8% | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 70.8% | Only Gemini 3.1 Pro Preview measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 6.7% | Only Gemini 3.1 Pro Preview measured |
| SciCode | 43.4% | 58.7% | Gemini 3.1 Pro Preview |
| Terminal-Bench Hard (Artificial Analysis run) | 24.2% | 53.8% | Gemini 3.1 Pro Preview |
| Terminal-Bench | Not measured | 80.2% | Only Gemini 3.1 Pro Preview measured |
| GSO-Bench | Not measured | 22.6% | Only Gemini 3.1 Pro Preview measured |
| WeirdML | 52.2% | 72.1% | Gemini 3.1 Pro Preview |
| MirrorCode | Not measured | 8.9% | Only Gemini 3.1 Pro Preview measured |
| ALE-Bench | Not measured | 1160.6 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: coding | Not measured | 1484 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: software and IT | Not measured | 1487 | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: React | Not measured | 1438 | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: HTML | Not measured | 1490 | Only Gemini 3.1 Pro Preview measured |
| LMArena WebDev: from an image | Not measured | 1481 | Only Gemini 3.1 Pro Preview measured |
| SciCode | Not measured | 14.3% | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 15 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 29.7 | Only Gemini 3.1 Pro Preview measured |
| Epoch Capabilities Index | 144.3 | Not measured | Only Gemini 3.1 Flash Lite measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 8.2 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building web apps | Not measured | 1125 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building full-stack apps | Not measured | 1068 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building mobile apps | Not measured | 1094 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Android apps | Not measured | 1049 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building Godot games | Not measured | 1236 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: agents building games | Not measured | 1113 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: HTML slides | Not measured | 1103 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: PowerPoint slides | Not measured | 1041 | Only Gemini 3.1 Pro Preview measured |
| SREBench (Vals AI) | Not measured | 0.0% | Only Gemini 3.1 Pro Preview measured |
| Finance Agent (Vals AI) | Not measured | 43.0% | Only Gemini 3.1 Pro Preview measured |
| Tax Agent Bench (Vals AI) | Not measured | 9.3% | Only Gemini 3.1 Pro Preview measured |
| Legal Research Bench (Vals AI) | Not measured | 20.7% | Only Gemini 3.1 Pro Preview measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 52.6% | Only Gemini 3.1 Pro Preview measured |
| BioMysteryBench (Vals AI) | Not measured | 60.0% | Only Gemini 3.1 Pro Preview measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 1.4% | Only Gemini 3.1 Pro Preview measured |
| Vals Science Index | Not measured | 27.4% | Only Gemini 3.1 Pro Preview measured |
| τ²-Bench Telecom | 31.3% | 95.6% | Gemini 3.1 Pro Preview |
| APEX-Agents | Not measured | 35.1% | Only Gemini 3.1 Pro Preview measured |
| METR time horizons | Not measured | 77.0% | Only Gemini 3.1 Pro Preview measured |
| BALROG | Not measured | 57.0% | Only Gemini 3.1 Pro Preview measured |
| DeepResearch Bench | 37.3% | 47.8% | Gemini 3.1 Pro Preview |
| PostTrainBench | Not measured | 22.0% | Only Gemini 3.1 Pro Preview measured |
| Vending-Bench 2 | Not measured | $911 | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 17 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 95.5% | Only Gemini 3.1 Pro Preview measured |
| MysteryMechanism (Vals AI) | Not measured | 20.7% | Only Gemini 3.1 Pro Preview measured |
| MMMU Pro (Vals AI) | Not measured | 88.2% | Only Gemini 3.1 Pro Preview measured |
| GPQA Diamond (Artificial Analysis run) | 82.2% | 94.1% | Gemini 3.1 Pro Preview |
| Humanity's Last Exam (Artificial Analysis run) | 17.2% | 47.0% | Gemini 3.1 Pro Preview |
| GPQA Diamond (Epoch AI run) | 81.8% | 94.4% | Gemini 3.1 Pro Preview |
| ARC-AGI | Not measured | 98.0% | Only Gemini 3.1 Pro Preview measured |
| ARC-AGI-2 | Not measured | 77.1% | Only Gemini 3.1 Pro Preview measured |
| SimpleBench | Not measured | 79.6% | Only Gemini 3.1 Pro Preview measured |
| Chess puzzles | Not measured | 51.0% | Only Gemini 3.1 Pro Preview measured |
| Mystery game puzzles | Not measured | 34.0% | Only Gemini 3.1 Pro Preview measured |
| EBR-bench | Not measured | 14.3% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts | Not measured | 1485 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: expert | Not measured | 1483 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: hard prompts in English | Not measured | 1480 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: diagrams | Not measured | 1311 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: homework | Not measured | 1316 | Only Gemini 3.1 Pro Preview measured |
| Kagi LLM Benchmark | 67.2% | Not measured | Only Gemini 3.1 Flash Lite measured |
| Neither model has a result on the other 4 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| AIME | Not measured | 98.1% | Only Gemini 3.1 Pro Preview measured |
| OTIS Mock AIME | 80.0% | 95.6% | Gemini 3.1 Pro Preview |
| FrontierMath, tiers 1 to 3 | 27.7% | 59.6% | Gemini 3.1 Pro Preview |
| FrontierMath, tier 4 | Not measured | 26.8% | Only Gemini 3.1 Pro Preview measured |
| ProofBench | Not measured | 26.0% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: math | Not measured | 1486 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: mathematical work | Not measured | 1478 | Only Gemini 3.1 Pro Preview measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index14 boards, none shared
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 91.0% | Only Gemini 3.1 Pro Preview measured |
| LegalBench (Vals AI) | Not measured | 87.4% | Only Gemini 3.1 Pro Preview measured |
| CaseLaw (Vals AI) | Not measured | 64.8% | Only Gemini 3.1 Pro Preview measured |
| CorpFin (Vals AI) | Not measured | 64.5% | Only Gemini 3.1 Pro Preview measured |
| TaxEval (Vals AI) | Not measured | 72.9% | Only Gemini 3.1 Pro Preview measured |
| MortgageTax (Vals AI) | Not measured | 69.4% | Only Gemini 3.1 Pro Preview measured |
| MedQA (Vals AI) | Not measured | 96.4% | Only Gemini 3.1 Pro Preview measured |
| MedCode (Vals AI) | Not measured | 59.1% | Only Gemini 3.1 Pro Preview measured |
| SimpleQA Verified | Not measured | 73.5% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: science | Not measured | 1497 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: medicine and healthcare | Not measured | 1486 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: legal and government | Not measured | 1487 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: business and finance | Not measured | 1459 | Only Gemini 3.1 Pro Preview measured |
| FACTS Benchmark Suite | Not measured | 67.4% | Only Gemini 3.1 Pro Preview measured |
| 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 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1233 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: UI components | Not measured | 1224 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: game dev | Not measured | 1202 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: data viz | Not measured | 1209 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: 3D | Not measured | 1234 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: all code categories | Not measured | 1231 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: SVG | Not measured | 1285 | Only Gemini 3.1 Pro Preview measured |
| Design Arena: ASCII art | Not measured | 1270 | 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 index13
| Benchmark | Gemini 3.1 Flash Lite | Gemini 3.1 Pro Preview | Leader |
|---|---|---|---|
| Public Benefits Bench (Vals AI) | Not measured | 53.8% | Only Gemini 3.1 Pro Preview measured |
| SAGE (Vals AI) | Not measured | 48.7% | Only Gemini 3.1 Pro Preview measured |
| MedScribe (Vals AI) | Not measured | 76.1% | Only Gemini 3.1 Pro Preview measured |
| Vals Multimodal Index | Not measured | 56.1% | Only Gemini 3.1 Pro Preview measured |
| IFBench | 77.2% | 77.1% | Gemini 3.1 Flash Lite |
| Long context reasoning (AA-LCR) | 74.3% | 82.0% | Gemini 3.1 Pro Preview |
| DTBench | 76.8% | 97.1% | Gemini 3.1 Pro Preview |
| LMCA | 35.0% | 53.8% | Gemini 3.1 Pro Preview |
| CL-bench | Not measured | 20.8% | Only Gemini 3.1 Pro Preview measured |
| Furniture assembly | Not measured | 26.7% | Only Gemini 3.1 Pro Preview measured |
| ExploitBench | Not measured | 26.1% | Only Gemini 3.1 Pro Preview measured |
| CL-bench Life | Not measured | 16.9% | Only Gemini 3.1 Pro Preview measured |
| LMArena Text | Not measured | 1480 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: instruction following | Not measured | 1466 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: creative writing | Not measured | 1482 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision | Not measured | 1296 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: English | Not measured | 1478 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: non-English | Not measured | 1476 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Chinese | Not measured | 1527 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: German | Not measured | 1490 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Japanese | Not measured | 1491 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Korean | Not measured | 1455 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: French | Not measured | 1487 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Spanish | Not measured | 1481 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Russian | Not measured | 1497 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: Polish | Not measured | 1498 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: multi-turn | Not measured | 1487 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: longer queries | Not measured | 1482 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: writing and language | Not measured | 1481 | Only Gemini 3.1 Pro Preview measured |
| LMArena Text: entertainment and media | Not measured | 1465 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: English | Not measured | 1287 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: Chinese | Not measured | 1364 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: reading text | Not measured | 1304 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: humor | Not measured | 1322 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: captioning | Not measured | 1345 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: recognizing things | Not measured | 1330 | Only Gemini 3.1 Pro Preview measured |
| LMArena Vision: creative writing | Not measured | 1324 | Only Gemini 3.1 Pro Preview measured |
| LMArena Document | Not measured | 1444 | 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 Flash Lite | Gemini 3.1 Pro Preview | 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 Flash Lite$0.0010Fits in one request
Gemini 3.1 Pro Preview$0.0080Fits in one request
Gemini 3.1 Flash Lite costs less
Repository review
50K input + 3K output tokens
Gemini 3.1 Flash Lite$0.017Fits in one request
Gemini 3.1 Pro Preview$0.136Fits in one request
Gemini 3.1 Flash Lite costs less
Agent loop
200K input + 10K output tokens
Gemini 3.1 Flash Lite$0.065Fits in one request
Gemini 3.1 Pro Preview$0.520Fits in one request
Gemini 3.1 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 Flash Lite | Google Gemini 3.1 Pro Preview |
|---|---|---|
| Maker | ||
| Weights | No public weights listed | No public weights listed |
| Released | May 7, 2026 | February 19, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.25 | $2.00 |
| Output $/Mtok | $1.50 | $12.00 |
| Coding index | Not benchmarked | 32.3 |
| Independent measurements behind it | 0 | 4 |
| Cost per solved task | Not computable | $0.99 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.1 Flash Lite better than Gemini 3.1 Pro Preview for coding?
Only Gemini 3.1 Pro Preview has a coding score, 32.3 on the Vibe Coding Index; Gemini 3.1 Flash Lite has none, so the two cannot be ranked on coding. Pick Gemini 3.1 Flash Lite for output tokens 8.0x cheaper ($1.50 vs $12.00 per million) and work measured by IFBench, where it leads.
Which is cheaper, Gemini 3.1 Flash Lite or Gemini 3.1 Pro Preview?
Gemini 3.1 Flash Lite costs $0.25 per million input tokens and $1.50 per million output tokens; Gemini 3.1 Pro Preview costs $2.00 and $12.00. Cost per solved task is known for Gemini 3.1 Pro Preview only.
Which has the bigger context window, Gemini 3.1 Flash Lite or Gemini 3.1 Pro Preview?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 3.1 Flash Lite vs Gemini 3.1 Pro Preview comparison based on?
14 benchmarks have a result for both models as of October 22, 2026. Gemini 3.1 Flash Lite's coding index rests on 0 independent benchmarks and Gemini 3.1 Pro Preview's on 4. Where only one model has a result, the page says so instead of naming a winner.