Gemini 3.8 Flash vs Kimi K2 Thinking
Gemini 3.8 Flash leads Kimi K2 Thinking on the Artificial Analysis Intelligence Index, 40.9 to 22.0, and Kimi K2 Thinking costs 1.5x less per output token ($2.50 vs $3.75 per million). Updated October 21, 2026; 14 benchmarks have a result for both.
vs boards won of 14 shared
Gemini 3.8 Flash or Kimi K2 Thinking: which to pick
Only Gemini 3.8 Flash has a coding score, 61.6 on the Vibe Coding Index; Kimi K2 Thinking has none, so the two cannot be ranked on coding.
Pick Kimi K2 Thinking for output tokens 1.5x cheaper ($2.50 vs $3.75 per million) and a lower cost per solved task ($0.61 against $2.74).
Model AGemini 3.8 FlashGoogle61.6/1006 independent benchmarks$2.74 per solved taskModel BKimi K2 ThinkingMoonshot AINot benchmarked1 independent benchmark$0.61 per solved task
- Shared results
- 14
- Gemini 3.8 Flash only
- 114
- Kimi K2 Thinking only
- 16
- 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
No call
Only Gemini 3.8 Flash has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 40.9 against 22.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 3.8 Flash has a AA Agentic Index result, 40.2.
Directional only
Reasoning
GPQA Diamond
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 94.4% against 78.5%.
Same board, both measured
Math
AIME
No call
Only Kimi K2 Thinking has a AIME result, 85.4%.
Directional only
Knowledge
MMLU Pro
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 90.2% against 81.1%.
Same board, both measured
Web design
Design Arena: websites
Gemini 3.8 Flash
Gemini 3.8 Flash leads, 1300 against 1113.
Same board, both measured
General
Vals Index
No call
Only Gemini 3.8 Flash has a Vals Index result, 56.0%.
Directional only
Long documents
Listed context window
Gemini 3.8 Flash
Gemini 3.8 Flash takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Kimi K2 Thinking
Gemini 3.8 Flash $0.0026, Kimi K2 Thinking $0.0019 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Kimi K2 Thinking
Gemini 3.8 Flash $2.74, Kimi K2 Thinking $0.61.
Published attempt cost and pass rate
At a glance
- Coding index
- Gemini 3.8 Flash 61.6 from 6 benchmarks, Kimi K2 Thinking not benchmarked.
- Widest category
- Coding, 27.6 points apart on average over 4 shared benchmarks.
- Widest single gap
- WeirdML: Gemini 3.8 Flash 84.8% against Kimi K2 Thinking 42.8%, 42.0 points apart on a 0 to 100 scale.
- Output price
- Gemini 3.8 Flash $3.75 against Kimi K2 Thinking $2.50 per million output tokens, 1.5x apart.
- Context window
- Gemini 3.8 Flash takes 1.05M tokens, Kimi K2 Thinking 262K.
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 3.8 Flash | Bars | Kimi K2 Thinking | Ties |
|---|---|---|---|---|
| Coding | 4 | 0 | ||
| Intelligence | 2 | 0 | ||
| Reasoning | 3 | 0 | ||
| Knowledge | 3 | 0 | ||
| Web design | 1 | 0 | ||
| General | 1 | 0 | ||
| All shared boards | 14 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index40
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| SWE-bench Verified | Not measured | 63.4% | Only Kimi K2 Thinking measured |
| LiveBench coding | 82.2% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev | 1585 | Not measured | Only Gemini 3.8 Flash measured |
| AA Coding Index | 76.3 | Not measured | Only Gemini 3.8 Flash measured |
| LiveCodeBench (Vals AI) | 89.5% | 63.1% | Gemini 3.8 Flash |
| SWE-bench Verified (Vals AI) | 80.0% | 60.2% | Gemini 3.8 Flash |
| Terminal-Bench 4 (Vals AI) | 19.7% | Not measured | Only Gemini 3.8 Flash measured |
| Vibe Code Bench (Vals AI) | 78.7% | Not measured | Only Gemini 3.8 Flash measured |
| Code migration (Vals AI) | 36.5% | Not measured | Only Gemini 3.8 Flash measured |
| ProgramBench (Vals AI) | 1.0% | Not measured | Only Gemini 3.8 Flash measured |
| IOI (Vals AI) | 56.9% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench 2.1 (Vals AI) | 81.3% | Not measured | Only Gemini 3.8 Flash measured |
| SWE-bench Multimodal (Vals AI) | 40.8% | Not measured | Only Gemini 3.8 Flash measured |
| Vibe Code Bench 1-100 (Vals AI) | 18.8% | Not measured | Only Gemini 3.8 Flash measured |
| SkillsBench (Vals AI) | 58.0% | Not measured | Only Gemini 3.8 Flash measured |
| CyberBench (Vals AI) | 43.8% | Not measured | Only Gemini 3.8 Flash measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 85.3% | Only Kimi K2 Thinking measured |
| SciCode | 56.6% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 31.1% | Only Kimi K2 Thinking measured |
| Terminal-Bench | Not measured | 35.7% | Only Kimi K2 Thinking measured |
| FrontierCode | 41.2% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierSWE | 19.6% | Not measured | Only Gemini 3.8 Flash measured |
| WeirdML | 84.8% | 42.8% | Gemini 3.8 Flash |
| ALE-Bench | 1269.7 | 597.5 | Gemini 3.8 Flash |
| LMArena Text: coding | 1508 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: software and IT | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev: React | 1577 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev: HTML | 1616 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena WebDev: from an image | 1593 | Not measured | Only Gemini 3.8 Flash measured |
| SciCode | 12.3% | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 9 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| AA Intelligence Index | 40.9 | 22.0 | Gemini 3.8 Flash |
| Epoch Capabilities Index | 157.4 | 145.8 | Gemini 3.8 Flash |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index27 boards, none shared
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| AA Agentic Index | 40.2 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building web apps | 1238 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building full-stack apps | 1244 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building mobile apps | 1236 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building Android apps | 1074 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: agents building Godot games | 1273 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: PowerPoint slides | 1177 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: spreadsheets | 1056 | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench research | 79.1% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench browser | 64.0% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench long agentic | 30.1% | Not measured | Only Gemini 3.8 Flash measured |
| SREBench (Vals AI) | 11.1% | Not measured | Only Gemini 3.8 Flash measured |
| Finance Agent (Vals AI) | 61.4% | Not measured | Only Gemini 3.8 Flash measured |
| Tax Agent Bench (Vals AI) | 32.1% | Not measured | Only Gemini 3.8 Flash measured |
| Legal Research Bench (Vals AI) | 38.9% | Not measured | Only Gemini 3.8 Flash measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 12.1% | Not measured | Only Gemini 3.8 Flash measured |
| Excel Modeling Benchmark (Vals AI) | 72.2% | Not measured | Only Gemini 3.8 Flash measured |
| BioMysteryBench (Vals AI) | 62.2% | Not measured | Only Gemini 3.8 Flash measured |
| Terminal-Bench-Science (Vals AI) | 8.6% | Not measured | Only Gemini 3.8 Flash measured |
| Vals Science Index | 35.8% | Not measured | Only Gemini 3.8 Flash measured |
| Time Horizon Index (Vals AI) | 18.8% | Not measured | Only Gemini 3.8 Flash measured |
| CUA-bench (Vals AI) | 4.2% | Not measured | Only Gemini 3.8 Flash measured |
| τ²-Bench Telecom | Not measured | 93.0% | Only Kimi K2 Thinking measured |
| APEX-Agents | 64.3% | Not measured | Only Gemini 3.8 Flash measured |
| METR time horizons | Not measured | 59.2% | Only Kimi K2 Thinking measured |
| Remote Labor Index | 5.8% | Not measured | Only Gemini 3.8 Flash measured |
| Vending-Bench 2 | $5,094 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| GPQA Diamond | 94.4% | 78.5% | Gemini 3.8 Flash |
| LiveBench reasoning | 89.3% | Not measured | Only Gemini 3.8 Flash measured |
| MysteryMechanism (Vals AI) | 36.5% | Not measured | Only Gemini 3.8 Flash measured |
| MMMU Pro (Vals AI) | 89.1% | Not measured | Only Gemini 3.8 Flash measured |
| GPQA Diamond (Artificial Analysis run) | 95.3% | 83.8% | Gemini 3.8 Flash |
| Humanity's Last Exam (Artificial Analysis run) | 47.8% | 23.8% | Gemini 3.8 Flash |
| GPQA Diamond (Epoch AI run) | 95.4% | Not measured | Only Gemini 3.8 Flash measured |
| ARC-AGI | 98.5% | Not measured | Only Gemini 3.8 Flash measured |
| ARC-AGI-2 | 89.2% | Not measured | Only Gemini 3.8 Flash measured |
| Chess puzzles | 58.0% | Not measured | Only Gemini 3.8 Flash measured |
| Mystery game puzzles | 47.0% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: hard prompts | 1509 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: expert | 1526 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: hard prompts in English | 1504 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: diagrams | 1345 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: homework | 1351 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 6 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| AIME | Not measured | 85.4% | Only Kimi K2 Thinking measured |
| MGSM (Vals AI) | Not measured | 90.2% | Only Kimi K2 Thinking measured |
| AA Math Index | Not measured | 94.7 | Only Kimi K2 Thinking measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 94.7% | Only Kimi K2 Thinking measured |
| OTIS Mock AIME | 98.9% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierMath, tiers 1 to 3 | 68.4% | Not measured | Only Gemini 3.8 Flash measured |
| FrontierMath, tier 4 | 22.0% | Not measured | Only Gemini 3.8 Flash measured |
| ProofBench | 48.0% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: math | 1532 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: mathematical work | 1519 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| MMLU Pro | 90.2% | 81.1% | Gemini 3.8 Flash |
| LegalBench (Vals AI) | 87.0% | 80.2% | Gemini 3.8 Flash |
| CaseLaw (Vals AI) | Not measured | 65.7% | Only Kimi K2 Thinking measured |
| CorpFin (Vals AI) | Not measured | 60.6% | Only Kimi K2 Thinking measured |
| TaxEval (Vals AI) | 74.5% | 71.7% | Gemini 3.8 Flash |
| MortgageTax (Vals AI) | 65.3% | Not measured | Only Gemini 3.8 Flash measured |
| MedQA (Vals AI) | Not measured | 92.6% | Only Kimi K2 Thinking measured |
| MedCode (Vals AI) | 48.1% | Not measured | Only Gemini 3.8 Flash measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 84.8% | Only Kimi K2 Thinking measured |
| SimpleQA Verified | 69.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: science | 1523 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: medicine and healthcare | 1508 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: legal and government | 1497 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: business and finance | 1479 | Not measured | Only Gemini 3.8 Flash measured |
| FACTS Benchmark Suite | 69.4% | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 3 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| Design Arena: websites | 1300 | 1113 | Gemini 3.8 Flash |
| Design Arena: UI components | 1319 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: game dev | 1305 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: data viz | 1269 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: 3D | 1295 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: all code categories | 1304 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: SVG | 1295 | Not measured | Only Gemini 3.8 Flash measured |
| Design Arena: ASCII art | 1265 | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench design | 72.7% | Not measured | Only Gemini 3.8 Flash measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | Leader |
|---|---|---|---|
| Vals Index | 56.0% | Not measured | Only Gemini 3.8 Flash measured |
| LiveBench data analysis | 54.0% | Not measured | Only Gemini 3.8 Flash measured |
| Public Benefits Bench (Vals AI) | 65.3% | Not measured | Only Gemini 3.8 Flash measured |
| SAGE (Vals AI) | 35.1% | Not measured | Only Gemini 3.8 Flash measured |
| MedScribe (Vals AI) | 84.5% | Not measured | Only Gemini 3.8 Flash measured |
| IFBench | Not measured | 68.1% | Only Kimi K2 Thinking measured |
| Long context reasoning (AA-LCR) | 84.0% | 72.0% | Gemini 3.8 Flash |
| DTBench | 95.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMCA | 52.9% | Not measured | Only Gemini 3.8 Flash measured |
| CL-bench | Not measured | 17.6% | Only Kimi K2 Thinking measured |
| Surface Evolver Bench | 76.9% | Not measured | Only Gemini 3.8 Flash measured |
| Furniture assembly | 31.7% | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text | 1499 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: instruction following | 1492 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: creative writing | 1488 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision | 1315 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: English | 1498 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: non-English | 1491 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Chinese | 1553 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: German | 1501 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Japanese | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Korean | 1464 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: French | 1496 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Spanish | 1487 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Russian | 1514 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: Polish | 1497 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: multi-turn | 1503 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: longer queries | 1507 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: writing and language | 1494 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Text: entertainment and media | 1480 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: English | 1318 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: Chinese | 1416 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: reading text | 1333 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: humor | 1321 | Not measured | Only Gemini 3.8 Flash measured |
| LMArena Vision: creative writing | 1299 | Not measured | Only Gemini 3.8 Flash measured |
| Neither model has a result on the other 11 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemini 3.8 Flash | Kimi K2 Thinking | 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 3.8 Flash$0.0026Fits in one request
Kimi K2 Thinking$0.0019Fits in one request
Kimi K2 Thinking costs less
Repository review
50K input + 3K output tokens
Gemini 3.8 Flash$0.049Fits in one request
Kimi K2 Thinking$0.037Fits in one request
Kimi K2 Thinking costs less
Agent loop
200K input + 10K output tokens
Gemini 3.8 Flash$0.188Fits in one request
Kimi K2 Thinking$0.145Fits in one request
Kimi K2 Thinking 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 3.8 Flash | MoonshotAI Kimi K2 Thinking |
|---|---|---|
| Maker | Moonshot AI | |
| Weights | No public weights listed | Open weights |
| Released | September 2, 2026 | November 6, 2025 |
| Context window | 1.05M | 262K |
| Input $/Mtok | $0.75 | $0.60 |
| Output $/Mtok | $3.75 | $2.50 |
| Coding index | 61.6 | Not benchmarked |
| Independent measurements behind it | 6 | 1 |
| Cost per solved task | $2.74 | $0.61 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemini 3.8 Flash better than Kimi K2 Thinking for coding?
Only Gemini 3.8 Flash has a coding score, 61.6 on the Vibe Coding Index; Kimi K2 Thinking has none, so the two cannot be ranked on coding. Pick Kimi K2 Thinking for output tokens 1.5x cheaper ($2.50 vs $3.75 per million) and a lower cost per solved task ($0.61 against $2.74).
Which is cheaper, Gemini 3.8 Flash or Kimi K2 Thinking?
Gemini 3.8 Flash costs $0.75 per million input tokens and $3.75 per million output tokens; Kimi K2 Thinking costs $0.60 and $2.50. Per solved SWE-bench Verified task, Gemini 3.8 Flash costs $2.74 and Kimi K2 Thinking $0.61.
Which has the bigger context window, Gemini 3.8 Flash or Kimi K2 Thinking?
Gemini 3.8 Flash, with 1.05M tokens against 262K.
How many benchmarks is the Gemini 3.8 Flash vs Kimi K2 Thinking comparison based on?
14 benchmarks have a result for both models as of October 21, 2026. Gemini 3.8 Flash's coding index rests on 6 independent benchmarks and Kimi K2 Thinking's on 1. Where only one model has a result, the page says so instead of naming a winner.