Gemma 4 31B vs Kimi K3.1 Pro
Kimi K3.1 Pro leads Gemma 4 31B on coding, 82.2 to 39.0 on the Vibe Coding Index, and Gemma 4 31B costs 25.0x less per output token ($0.40 vs $10.00 per million). Updated October 29, 2026; 14 benchmarks have a result for both.
Gemma 4 31B 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 39.0 for Gemma 4 31B.
Pick Gemma 4 31B for output tokens 25.0x cheaper ($0.40 vs $10.00 per million).
- Shared results
- 14
- Gemma 4 31B only
- 57
- Kimi K3.1 Pro only
- 21
- 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
Kimi K3.1 Pro
Kimi K3.1 Pro scores 82.2 against 39.0.
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
Agentic work
AA Agentic Index
No call
Only Gemma 4 31B has a AA Agentic Index result, 4.2.
Directional only
Web design
Design Arena: websites
No call
Only Kimi K3.1 Pro has a Design Arena: websites result, 1325.
Directional only
General
Vals Index
No call
Only Kimi K3.1 Pro has a Vals Index result, 62.5%.
Directional only
Long documents
Listed context window
Kimi K3.1 Pro
Kimi K3.1 Pro takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemma 4 31B
Gemma 4 31B $0.0003, Kimi K3.1 Pro $0.0070 per turn.
List prices
At a glance
- Coding index
- Gemma 4 31B 39.0 from 2 benchmarks, Kimi K3.1 Pro 82.2 from 4 benchmarks.
- Widest category
- Agentic work, 45.9 points apart on average over 3 shared benchmarks.
- Widest single gap
- LiveBench browser: Gemma 4 31B 0.0% against Kimi K3.1 Pro 75.9%, 75.9 points apart on a 0 to 100 scale.
- Output price
- Gemma 4 31B $0.40 against Kimi K3.1 Pro $10.00 per million output tokens, 25.0x apart.
- Context window
- Gemma 4 31B takes 262K tokens, Kimi K3.1 Pro 1.05M.
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 | Gemma 4 31B | Bars | Kimi K3.1 Pro | Ties |
|---|---|---|---|---|
| Coding | 0 | 6 | ||
| Agentic work | 0 | 3 | ||
| Reasoning | 0 | 2 | ||
| Web design | 0 | 1 | ||
| General | 0 | 2 | ||
| All shared boards | 0 | 14 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index06
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| LiveBench coding | 49.0% | 81.8% | Kimi K3.1 Pro |
| LMArena WebDev | 1369 | 1695 | Kimi K3.1 Pro |
| AA Coding Index | 43.4 | Not measured | Only Gemma 4 31B measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 63.6% | Only Kimi K3.1 Pro measured |
| Vibe Code Bench (Vals AI) | Not measured | 84.9% | Only Kimi K3.1 Pro measured |
| IOI (Vals AI) | Not measured | 81.9% | Only Kimi K3.1 Pro measured |
| SciCode | 45.5% | 60.8% | Kimi K3.1 Pro |
| Terminal-Bench Hard (Artificial Analysis run) | 36.4% | Not measured | Only Gemma 4 31B measured |
| WeirdML | 52.3% | Not measured | Only Gemma 4 31B measured |
| ALE-Bench | 925.5 | 1932.8 | Kimi K3.1 Pro |
| LMArena Text: coding | 1459 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: software and IT | 1463 | Not measured | Only Gemma 4 31B measured |
| LMArena WebDev: React | 1361 | 1701 | Kimi K3.1 Pro |
| LMArena WebDev: HTML | 1381 | 1706 | Kimi K3.1 Pro |
| SciCode | 8.9% | Not measured | Only Gemma 4 31B measured |
| Neither model has a result on the other 28 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 46.0 | Only Kimi K3.1 Pro measured |
| Epoch Capabilities Index | 143.0 | Not measured | Only Gemma 4 31B measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| AA Agentic Index | 4.2 | Not measured | Only Gemma 4 31B measured |
| LiveBench research | 44.4% | 77.9% | Kimi K3.1 Pro |
| LiveBench browser | 0.0% | 75.9% | Kimi K3.1 Pro |
| LiveBench long agentic | 10.7% | 39.1% | Kimi K3.1 Pro |
| Tax Agent Bench (Vals AI) | Not measured | 24.9% | Only Kimi K3.1 Pro measured |
| Legal Research Bench (Vals AI) | Not measured | 37.5% | Only Kimi K3.1 Pro measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 11.7% | Only Kimi K3.1 Pro 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 | 65.5% | Not measured | Only Gemma 4 31B measured |
| Neither model has a result on the other 31 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| LiveBench reasoning | 68.3% | 91.1% | Kimi K3.1 Pro |
| MysteryMechanism (Vals AI) | Not measured | 26.1% | Only Kimi K3.1 Pro measured |
| GPQA Diamond (Artificial Analysis run) | 85.7% | Not measured | Only Gemma 4 31B measured |
| Humanity's Last Exam (Artificial Analysis run) | 23.6% | 52.5% | Kimi K3.1 Pro |
| GPQA Diamond (Epoch AI run) | 75.8% | Not measured | Only Gemma 4 31B measured |
| LMArena Text: hard prompts | 1448 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: expert | 1465 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: hard prompts in English | 1456 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: diagrams | 1283 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: homework | 1310 | Not measured | Only Gemma 4 31B measured |
| Kagi LLM Benchmark | 63.5% | Not measured | Only Gemma 4 31B measured |
| Neither model has a result on the other 12 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| OTIS Mock AIME | 73.3% | Not measured | Only Gemma 4 31B measured |
| ProofBench | Not measured | 91.0% | Only Kimi K3.1 Pro measured |
| LMArena Text: math | 1464 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: mathematical work | 1465 | Not measured | Only Gemma 4 31B measured |
| MathArena | Not measured | 59.6% | Only Kimi K3.1 Pro measured |
| Neither model has a result on the other 9 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| CaseLaw (Vals AI) | 52.6% | Not measured | Only Gemma 4 31B measured |
| MortgageTax (Vals AI) | 61.4% | Not measured | Only Gemma 4 31B measured |
| SimpleQA Verified | 10.4% | Not measured | Only Gemma 4 31B measured |
| LMArena Text: science | 1457 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: medicine and healthcare | 1450 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: legal and government | 1438 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: business and finance | 1430 | Not measured | Only Gemma 4 31B measured |
| FACTS Benchmark Suite | 56.2% | Not measured | Only Gemma 4 31B measured |
| Neither model has a result on the other 12 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1325 | Only Kimi K3.1 Pro measured |
| Design Arena: UI components | Not measured | 1400 | Only Kimi K3.1 Pro measured |
| Design Arena: game dev | Not measured | 1410 | Only Kimi K3.1 Pro measured |
| Design Arena: data viz | Not measured | 1300 | Only Kimi K3.1 Pro measured |
| Design Arena: 3D | Not measured | 1451 | Only Kimi K3.1 Pro measured |
| Design Arena: all code categories | Not measured | 1354 | Only Kimi K3.1 Pro measured |
| Design Arena: SVG | Not measured | 1328 | Only Kimi K3.1 Pro measured |
| LiveBench design | 58.4% | 77.8% | Kimi K3.1 Pro |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | Gemma 4 31B | Kimi K3.1 Pro | Leader |
|---|---|---|---|
| Vals Index | Not measured | 62.5% | Only Kimi K3.1 Pro measured |
| LiveBench data analysis | 53.3% | 79.1% | Kimi K3.1 Pro |
| SAGE (Vals AI) | 82.8% | Not measured | Only Gemma 4 31B measured |
| IFBench | 75.6% | Not measured | Only Gemma 4 31B measured |
| Long context reasoning (AA-LCR) | 69.7% | 86.3% | Kimi K3.1 Pro |
| DTBench | 82.7% | Not measured | Only Gemma 4 31B measured |
| LMCA | 39.3% | Not measured | Only Gemma 4 31B measured |
| Surface Evolver Bench | 30.6% | Not measured | Only Gemma 4 31B measured |
| LMArena Text | 1443 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: instruction following | 1434 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: creative writing | 1416 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision | 1276 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: English | 1451 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: non-English | 1431 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: Chinese | 1475 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: French | 1436 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: Spanish | 1444 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: Russian | 1461 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: Polish | 1431 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: multi-turn | 1452 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: longer queries | 1446 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: writing and language | 1432 | Not measured | Only Gemma 4 31B measured |
| LMArena Text: entertainment and media | 1405 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: English | 1271 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: Chinese | 1326 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: reading text | 1282 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: humor | 1280 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: captioning | 1218 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: recognizing things | 1226 | Not measured | Only Gemma 4 31B measured |
| LMArena Vision: creative writing | 1285 | Not measured | Only Gemma 4 31B measured |
| LMArena Document | 1425 | Not measured | Only Gemma 4 31B measured |
| EQ-Bench 4 | 1110 | Not measured | Only Gemma 4 31B measured |
| Neither model has a result on the other 16 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Gemma 4 31B | 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
Gemma 4 31B costs less
Repository review
50K input + 3K output tokens
Gemma 4 31B costs less
Agent loop
200K input + 10K output tokens
Gemma 4 31B 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 Gemma 4 31B | MoonshotAI Kimi K3.1 Pro |
|---|---|---|
| Maker | Moonshot AI | |
| Weights | Open weights | No public weights listed |
| Released | April 2, 2026 | October 23, 2026 |
| Context window | 262K | 1.05M |
| Input $/Mtok | $0.14 | $2.00 |
| Output $/Mtok | $0.40 | $10.00 |
| Coding index | 39.0 | 82.2 |
| Independent measurements behind it | 2 | 4 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Gemma 4 31B 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 39.0 for Gemma 4 31B. Pick Gemma 4 31B for output tokens 25.0x cheaper ($0.40 vs $10.00 per million).
Which is cheaper, Gemma 4 31B or Kimi K3.1 Pro?
Gemma 4 31B costs $0.14 per million input tokens and $0.40 per million output tokens; Kimi K3.1 Pro costs $2.00 and $10.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Gemma 4 31B or Kimi K3.1 Pro?
Kimi K3.1 Pro, with 1.05M tokens against 262K.
How many benchmarks is the Gemma 4 31B vs Kimi K3.1 Pro comparison based on?
14 benchmarks have a result for both models as of October 29, 2026. Gemma 4 31B'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.