Gemini 3 Flash Preview vs Kimi K3.1 Pro
Kimi K3.1 Pro leads Gemini 3 Flash Preview on coding, 82.2 to 43.7 on the Vibe Coding Index, and Gemini 3 Flash Preview costs 3.3x less per output token ($3.00 vs $10.00 per million). Updated October 29, 2026; 11 benchmarks have a result for both.
Gemini 3 Flash Preview or Kimi K3.1 Pro: which to pick
Pick Kimi K3.1 Pro for coding: it scores 82.2 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview.
Pick Gemini 3 Flash Preview for output tokens 3.3x cheaper ($3.00 vs $10.00 per million).
- Shared results
- 11
- Gemini 3 Flash Preview only
- 58
- Kimi K3.1 Pro only
- 24
- Like-for-like categories
- 6 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
Kimi K3.1 Pro
Kimi K3.1 Pro scores 82.2 against 43.7.
2 and 4 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Kimi K3.1 Pro has a AA Intelligence Index result, 46.0.
Directional only
Reasoning
GPQA Diamond
No call
Only Gemini 3 Flash Preview has a GPQA Diamond result, 87.9%.
Directional only
Math
AIME
No call
Only Gemini 3 Flash Preview has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Gemini 3 Flash Preview has a MMLU Pro result, 88.6%.
Directional only
Web design
Design Arena: websites
Kimi K3.1 Pro
Kimi K3.1 Pro leads, 1325 against 1195.
Same board, both measured
General
Vals Index
No call
Only Kimi K3.1 Pro has a Vals Index result, 62.5%.
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 Flash Preview
Gemini 3 Flash Preview $0.0020, Kimi K3.1 Pro $0.0070 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Gemini 3 Flash Preview has the number, $0.37.
Directional only
At a glance
- Coding index
- Gemini 3 Flash Preview 43.7 from 2 benchmarks, Kimi K3.1 Pro 82.2 from 4 benchmarks.
- Widest category
- Math, 76.0 points apart on average over 1 shared benchmark.
- Widest single gap
- ProofBench: Gemini 3 Flash Preview 15.0% against Kimi K3.1 Pro 91.0%, 76.0 points apart on a 0 to 100 scale.
- Output price
- Gemini 3 Flash Preview $3.00 against Kimi K3.1 Pro $10.00 per million output tokens, 3.3x 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 Flash Preview | Bars | Kimi K3.1 Pro | Ties |
|---|---|---|---|---|
| Coding | 0 | 2 | ||
| Agentic work | 0 | 2 | ||
| Reasoning | 0 | 1 | ||
| Math | 0 | 1 | ||
| Web design | 0 | 4 | ||
| General | 0 | 1 | ||
| All shared boards | 0 | 11 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index02
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| SWE-bench Verified | 75.8% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveBench coding | Not measured | 81.8% | Only Kimi K3.1 Pro measured |
| LMArena WebDev | Not measured | 1695 | Only Kimi K3.1 Pro measured |
| LiveCodeBench (Vals AI) | 85.6% | Not measured | Only Gemini 3 Flash Preview measured |
| SWE-bench Verified (Vals AI) | 75.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 63.6% | Only Kimi K3.1 Pro measured |
| Vibe Code Bench (Vals AI) | 20.2% | 84.9% | Kimi K3.1 Pro |
| Code migration (Vals AI) | 6.4% | Not measured | Only Gemini 3 Flash Preview measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Gemini 3 Flash Preview measured |
| IOI (Vals AI) | Not measured | 81.9% | Only Kimi K3.1 Pro measured |
| Terminal-Bench 2.1 (Vals AI) | 53.9% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveCodeBench (Artificial Analysis run) | 90.8% | Not measured | Only Gemini 3 Flash Preview measured |
| SciCode | Not measured | 60.8% | Only Kimi K3.1 Pro measured |
| Terminal-Bench Hard (Artificial Analysis run) | 38.6% | Not measured | Only Gemini 3 Flash Preview measured |
| Terminal-Bench | 64.3% | Not measured | Only Gemini 3 Flash Preview measured |
| GSO-Bench | 9.8% | Not measured | Only Gemini 3 Flash Preview measured |
| WeirdML | 61.6% | Not measured | Only Gemini 3 Flash Preview measured |
| ALE-Bench | 1367.2 | 1932.8 | Kimi K3.1 Pro |
| LMArena WebDev: React | Not measured | 1701 | Only Kimi K3.1 Pro measured |
| LMArena WebDev: HTML | Not measured | 1706 | Only Kimi K3.1 Pro measured |
| SciCode | 12.7% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 22 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 46.0 | Only Kimi K3.1 Pro measured |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1112 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building full-stack apps | 1063 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building mobile apps | 1089 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building Android apps | 1048 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: agents building Godot games | 1161 | Not measured | Only Gemini 3 Flash Preview measured |
| Design Arena: PowerPoint slides | 1036 | Not measured | Only Gemini 3 Flash Preview measured |
| LiveBench research | Not measured | 77.9% | Only Kimi K3.1 Pro measured |
| LiveBench browser | Not measured | 75.9% | Only Kimi K3.1 Pro measured |
| LiveBench long agentic | Not measured | 39.1% | Only Kimi K3.1 Pro measured |
| Finance Agent (Vals AI) | 42.5% | Not measured | Only Gemini 3 Flash Preview measured |
| Tax Agent Bench (Vals AI) | 11.8% | 24.9% | Kimi K3.1 Pro |
| Legal Research Bench (Vals AI) | 18.3% | 37.5% | Kimi K3.1 Pro |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 11.7% | Only Kimi K3.1 Pro measured |
| Excel Modeling Benchmark (Vals AI) | 26.0% | Not measured | Only Gemini 3 Flash Preview measured |
| BioMysteryBench (Vals AI) | Not measured | 75.6% | Only Kimi K3.1 Pro measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 31.4% | Only Kimi K3.1 Pro measured |
| Vals Science Index | Not measured | 44.4% | Only Kimi K3.1 Pro measured |
| τ²-Bench Telecom | 80.4% | Not measured | Only Gemini 3 Flash Preview measured |
| BALROG | 48.1% | Not measured | Only Gemini 3 Flash Preview measured |
| DeepResearch Bench | 49.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Vending-Bench 2 | $3,635 | Not measured | Only Gemini 3 Flash Preview measured |
| MCP Atlas | 62.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 20 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| GPQA Diamond | 87.9% | Not measured | Only Gemini 3 Flash Preview measured |
| LiveBench reasoning | Not measured | 91.1% | Only Kimi K3.1 Pro measured |
| MysteryMechanism (Vals AI) | Not measured | 26.1% | Only Kimi K3.1 Pro measured |
| MMMU Pro (Vals AI) | 87.6% | Not measured | Only Gemini 3 Flash Preview measured |
| GPQA Diamond (Artificial Analysis run) | 89.8% | Not measured | Only Gemini 3 Flash Preview measured |
| Humanity's Last Exam (Artificial Analysis run) | 36.6% | 52.5% | Kimi K3.1 Pro |
| GPQA Diamond (Epoch AI run) | 89.4% | Not measured | Only Gemini 3 Flash Preview measured |
| ARC-AGI | 84.7% | Not measured | Only Gemini 3 Flash Preview measured |
| ARC-AGI-2 | 33.6% | Not measured | Only Gemini 3 Flash Preview measured |
| SimpleBench | 61.1% | Not measured | Only Gemini 3 Flash Preview measured |
| Chess puzzles | 39.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Mystery game puzzles | 26.0% | Not measured | Only Gemini 3 Flash Preview measured |
| VPCT | 72.6% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 10 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AIME | 95.6% | Not measured | Only Gemini 3 Flash Preview measured |
| MGSM (Vals AI) | 93.3% | Not measured | Only Gemini 3 Flash Preview measured |
| AIME 2025 (Artificial Analysis run) | 97.0% | Not measured | Only Gemini 3 Flash Preview measured |
| OTIS Mock AIME | 95.6% | Not measured | Only Gemini 3 Flash Preview measured |
| FrontierMath, tiers 1 to 3 | 51.2% | Not measured | Only Gemini 3 Flash Preview measured |
| FrontierMath, tier 4 | 17.1% | Not measured | Only Gemini 3 Flash Preview measured |
| ProofBench | 15.0% | 91.0% | Kimi K3.1 Pro |
| MathArena | Not measured | 59.6% | Only Kimi K3.1 Pro measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index12 boards, none shared
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| MMLU Pro | 88.6% | Not measured | Only Gemini 3 Flash Preview measured |
| LegalBench (Vals AI) | 86.9% | Not measured | Only Gemini 3 Flash Preview measured |
| CaseLaw (Vals AI) | 55.8% | Not measured | Only Gemini 3 Flash Preview measured |
| CorpFin (Vals AI) | 66.4% | Not measured | Only Gemini 3 Flash Preview measured |
| TaxEval (Vals AI) | 73.9% | Not measured | Only Gemini 3 Flash Preview measured |
| MortgageTax (Vals AI) | 68.7% | Not measured | Only Gemini 3 Flash Preview measured |
| MedQA (Vals AI) | 95.8% | Not measured | Only Gemini 3 Flash Preview measured |
| MedCode (Vals AI) | 55.9% | Not measured | Only Gemini 3 Flash Preview measured |
| MMLU Pro (Artificial Analysis run) | 89.0% | Not measured | Only Gemini 3 Flash Preview measured |
| SimpleQA Verified | 66.8% | Not measured | Only Gemini 3 Flash Preview measured |
| GeoBench | 88.0% | Not measured | Only Gemini 3 Flash Preview measured |
| FACTS Benchmark Suite | 64.9% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 8 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Design Arena: websites | 1195 | 1325 | Kimi K3.1 Pro |
| Design Arena: UI components | Not measured | 1400 | Only Kimi K3.1 Pro measured |
| Design Arena: game dev | 1165 | 1410 | Kimi K3.1 Pro |
| Design Arena: data viz | Not measured | 1300 | Only Kimi K3.1 Pro measured |
| Design Arena: 3D | 1180 | 1451 | Kimi K3.1 Pro |
| Design Arena: all code categories | 1188 | 1354 | Kimi K3.1 Pro |
| Design Arena: SVG | Not measured | 1328 | Only Kimi K3.1 Pro measured |
| LiveBench design | Not measured | 77.8% | Only Kimi K3.1 Pro measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Vals Index | Not measured | 62.5% | Only Kimi K3.1 Pro measured |
| LiveBench data analysis | Not measured | 79.1% | Only Kimi K3.1 Pro measured |
| MedScribe (Vals AI) | 69.9% | Not measured | Only Gemini 3 Flash Preview measured |
| Vals Multimodal Index | 52.2% | Not measured | Only Gemini 3 Flash Preview measured |
| IFBench | 78.0% | Not measured | Only Gemini 3 Flash Preview measured |
| Long context reasoning (AA-LCR) | 78.0% | 86.3% | Kimi K3.1 Pro |
| DTBench | 89.1% | Not measured | Only Gemini 3 Flash Preview measured |
| LMCA | 43.1% | Not measured | Only Gemini 3 Flash Preview measured |
| Neither model has a result on the other 40 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3 Flash Preview | Kimi K3.1 Pro | 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 Flash Preview costs less
Repository review
50K input + 3K output tokens
Gemini 3 Flash Preview costs less
Agent loop
200K input + 10K output tokens
Gemini 3 Flash Preview 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 Flash Preview | MoonshotAI Kimi K3.1 Pro |
|---|---|---|
| Maker | Moonshot AI | |
| Weights | No public weights listed | No public weights listed |
| Released | December 17, 2025 | October 23, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $0.50 | $2.00 |
| Output $/Mtok | $3.00 | $10.00 |
| Coding index | 43.7 | 82.2 |
| Independent measurements behind it | 2 | 4 |
| Cost per solved task | $0.37 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3 Flash Preview better than Kimi K3.1 Pro for coding?
Pick Kimi K3.1 Pro for coding: it scores 82.2 on the Vibe Coding Index against 43.7 for Gemini 3 Flash Preview. Pick Gemini 3 Flash Preview for output tokens 3.3x cheaper ($3.00 vs $10.00 per million).
Which is cheaper, Gemini 3 Flash Preview or Kimi K3.1 Pro?
Gemini 3 Flash Preview costs $0.50 per million input tokens and $3.00 per million output tokens; Kimi K3.1 Pro costs $2.00 and $10.00. Cost per solved task is known for Gemini 3 Flash Preview only.
Which has the bigger context window, Gemini 3 Flash Preview or Kimi K3.1 Pro?
Neither: both take 1.05M tokens.
How many benchmarks is the Gemini 3 Flash Preview vs Kimi K3.1 Pro comparison based on?
11 benchmarks have a result for both models as of October 29, 2026. Gemini 3 Flash Preview's coding index rests on 2 independent benchmarks and Kimi K3.1 Pro's on 4. Where only one model has a result, the page says so instead of naming a winner.