gpt-oss-20b vs Kimi K3
Kimi K3 leads gpt-oss-20b on the Artificial Analysis Intelligence Index, 43.6 to 10.0, and gpt-oss-20b costs 100.0x less per output token ($0.15 vs $15.00 per million). Updated October 21, 2026; 47 benchmarks have a result for both.
gpt-oss-20b or Kimi K3: which to pick
Only Kimi K3 has a coding score, 62.3 on the Vibe Coding Index; gpt-oss-20b has none, so the two cannot be ranked on coding.
Pick gpt-oss-20b for output tokens 100.0x cheaper ($0.15 vs $15.00 per million).
- Shared results
- 47
- gpt-oss-20b only
- 13
- Kimi K3 only
- 70
- Like-for-like categories
- 7 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 Kimi K3 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Kimi K3
Kimi K3 leads, 43.6 against 10.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Kimi K3 has a AA Agentic Index result, 50.0.
Directional only
Reasoning
GPQA Diamond
Kimi K3
Kimi K3 leads, 92.9% against 68.9%.
Same board, both measured
Math
AIME
No call
Only gpt-oss-20b has a AIME result, 86.0%.
Directional only
Knowledge
MMLU Pro
Kimi K3
Kimi K3 leads, 88.0% against 71.6%.
Same board, both measured
Web design
Design Arena: websites
Kimi K3
Kimi K3 leads, 1335 against 852.
Same board, both measured
General
Vals Index
No call
Only Kimi K3 has a Vals Index result, 53.0%.
Directional only
Long documents
Listed context window
Kimi K3
Kimi K3 takes 1.05M tokens against 131K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
gpt-oss-20b
gpt-oss-20b $0.0001, Kimi K3 $0.011 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Kimi K3 has the number, $0.81.
Directional only
At a glance
- Coding index
- gpt-oss-20b not benchmarked, Kimi K3 62.3 from 6 benchmarks.
- Widest category
- Web design, 56.3 points apart on average over 2 shared benchmarks.
- Widest single gap
- Design Arena: websites: gpt-oss-20b 852 against Kimi K3 1335, 60.4 points apart on a 0 to 100 scale.
- Output price
- gpt-oss-20b $0.15 against Kimi K3 $15.00 per million output tokens, 100.0x apart.
- Context window
- gpt-oss-20b takes 131K tokens, Kimi K3 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 | gpt-oss-20b | Bars | Kimi K3 | Ties |
|---|---|---|---|---|
| Coding | 0 | 6 | ||
| Intelligence | 0 | 2 | ||
| Reasoning | 0 | 7 | ||
| Math | 0 | 3 | ||
| Knowledge | 0 | 8 | ||
| Web design | 0 | 2 | ||
| General | 0 | 19 | ||
| All shared boards | 0 | 47 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index06
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 59.3% | Only Kimi K3 measured |
| LMArena WebDev | Not measured | 1655 | Only Kimi K3 measured |
| AA Coding Index | Not measured | 76.2 | Only Kimi K3 measured |
| LiveCodeBench (Vals AI) | 80.4% | 87.2% | Kimi K3 |
| SWE-bench Verified (Vals AI) | Not measured | 93.4% | Only Kimi K3 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 17.2% | Only Kimi K3 measured |
| Vibe Code Bench (Vals AI) | Not measured | 85.0% | Only Kimi K3 measured |
| Code migration (Vals AI) | Not measured | 16.1% | Only Kimi K3 measured |
| ProgramBench (Vals AI) | Not measured | 2.0% | Only Kimi K3 measured |
| IOI (Vals AI) | Not measured | 48.9% | Only Kimi K3 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 80.9% | Only Kimi K3 measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 44.2% | Only Kimi K3 measured |
| Vibe Code Bench 1-100 (Vals AI) | Not measured | 18.2% | Only Kimi K3 measured |
| CyberBench (Vals AI) | Not measured | 75.2% | Only Kimi K3 measured |
| LiveCodeBench (Artificial Analysis run) | 77.7% | Not measured | Only gpt-oss-20b measured |
| SciCode | 38.9% | 59.5% | Kimi K3 |
| Terminal-Bench Hard (Artificial Analysis run) | 10.6% | Not measured | Only gpt-oss-20b measured |
| Terminal-Bench | 3.4% | Not measured | Only gpt-oss-20b measured |
| FrontierCode | Not measured | 44.2% | Only Kimi K3 measured |
| FrontierSWE | Not measured | 25.9% | Only Kimi K3 measured |
| WeirdML | 40.9% | 82.6% | Kimi K3 |
| ALE-Bench | 566.0 | 1524.5 | Kimi K3 |
| LMArena Text: coding | 1307 | 1508 | Kimi K3 |
| LMArena Text: software and IT | 1311 | 1499 | Kimi K3 |
| LMArena WebDev: React | Not measured | 1670 | Only Kimi K3 measured |
| LMArena WebDev: HTML | Not measured | 1644 | Only Kimi K3 measured |
| LMArena WebDev: from an image | Not measured | 1579 | Only Kimi K3 measured |
| Neither model has a result on the other 11 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| AA Intelligence Index | 10.0 | 43.6 | Kimi K3 |
| Epoch Capabilities Index | 137.7 | 157.9 | Kimi K3 |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index25 boards, none shared
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 50.0 | Only Kimi K3 measured |
| Design Arena: agents building web apps | Not measured | 1295 | Only Kimi K3 measured |
| Design Arena: agents building full-stack apps | Not measured | 1315 | Only Kimi K3 measured |
| Design Arena: agents building mobile apps | Not measured | 1269 | Only Kimi K3 measured |
| Design Arena: agents building Android apps | Not measured | 1250 | Only Kimi K3 measured |
| Design Arena: agents building Godot games | Not measured | 1223 | Only Kimi K3 measured |
| Design Arena: agents building games | Not measured | 1252 | Only Kimi K3 measured |
| Design Arena: HTML slides | Not measured | 1256 | Only Kimi K3 measured |
| Design Arena: PowerPoint slides | Not measured | 1273 | Only Kimi K3 measured |
| Design Arena: spreadsheets | Not measured | 1058 | Only Kimi K3 measured |
| LiveBench research | Not measured | 79.0% | Only Kimi K3 measured |
| LiveBench browser | Not measured | 16.0% | Only Kimi K3 measured |
| LiveBench long agentic | Not measured | 42.8% | Only Kimi K3 measured |
| Finance Agent (Vals AI) | Not measured | 53.1% | Only Kimi K3 measured |
| Tax Agent Bench (Vals AI) | Not measured | 33.4% | Only Kimi K3 measured |
| Legal Research Bench (Vals AI) | Not measured | 46.1% | Only Kimi K3 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 12.9% | Only Kimi K3 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 66.7% | Only Kimi K3 measured |
| BioMysteryBench (Vals AI) | Not measured | 72.6% | Only Kimi K3 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 1.4% | Only Kimi K3 measured |
| Time Horizon Index (Vals AI) | Not measured | 10.5% | Only Kimi K3 measured |
| τ²-Bench Telecom | 60.2% | Not measured | Only gpt-oss-20b measured |
| APEX-Agents | Not measured | 47.8% | Only Kimi K3 measured |
| PostTrainBench | Not measured | 32.0% | Only Kimi K3 measured |
| Vending-Bench 2 | Not measured | $5,165 | Only Kimi K3 measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index07
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| GPQA Diamond | 68.9% | 92.9% | Kimi K3 |
| LiveBench reasoning | Not measured | 90.7% | Only Kimi K3 measured |
| MMMU Pro (Vals AI) | Not measured | 88.2% | Only Kimi K3 measured |
| GPQA Diamond (Artificial Analysis run) | 68.8% | 93.5% | Kimi K3 |
| Humanity's Last Exam (Artificial Analysis run) | 11.0% | 46.9% | Kimi K3 |
| GPQA Diamond (Epoch AI run) | 60.8% | 93.1% | Kimi K3 |
| ARC-AGI | Not measured | 94.5% | Only Kimi K3 measured |
| ARC-AGI-2 | Not measured | 60.4% | Only Kimi K3 measured |
| SimpleBench | Not measured | 60.7% | Only Kimi K3 measured |
| Chess puzzles | Not measured | 37.0% | Only Kimi K3 measured |
| Mystery game puzzles | Not measured | 26.0% | Only Kimi K3 measured |
| LMArena Text: hard prompts | 1274 | 1495 | Kimi K3 |
| LMArena Text: expert | 1258 | 1520 | Kimi K3 |
| LMArena Text: hard prompts in English | 1292 | 1496 | Kimi K3 |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| AIME | 86.0% | Not measured | Only gpt-oss-20b measured |
| MATH 500 (Vals AI) | 94.2% | Not measured | Only gpt-oss-20b measured |
| MGSM (Vals AI) | 89.0% | Not measured | Only gpt-oss-20b measured |
| AA Math Index | 89.3 | Not measured | Only gpt-oss-20b measured |
| AIME 2025 (Artificial Analysis run) | 89.3% | Not measured | Only gpt-oss-20b measured |
| OTIS Mock AIME | 65.3% | 97.2% | Kimi K3 |
| FrontierMath, tiers 1 to 3 | Not measured | 72.2% | Only Kimi K3 measured |
| FrontierMath, tier 4 | Not measured | 39.0% | Only Kimi K3 measured |
| ProofBench | Not measured | 87.0% | Only Kimi K3 measured |
| LMArena Text: math | 1317 | 1494 | Kimi K3 |
| LMArena Text: mathematical work | 1305 | 1505 | Kimi K3 |
| Neither model has a result on the other 2 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index08
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| MMLU Pro | 71.6% | 88.0% | Kimi K3 |
| LegalBench (Vals AI) | 70.8% | 86.2% | Kimi K3 |
| CaseLaw (Vals AI) | 43.8% | Not measured | Only gpt-oss-20b measured |
| CorpFin (Vals AI) | 53.1% | 71.6% | Kimi K3 |
| TaxEval (Vals AI) | 63.7% | 75.7% | Kimi K3 |
| MortgageTax (Vals AI) | Not measured | 66.3% | Only Kimi K3 measured |
| MedQA (Vals AI) | 82.9% | Not measured | Only gpt-oss-20b measured |
| MedCode (Vals AI) | Not measured | 49.4% | Only Kimi K3 measured |
| MMLU Pro (Artificial Analysis run) | 74.8% | Not measured | Only gpt-oss-20b measured |
| SimpleQA Verified | Not measured | 50.6% | Only Kimi K3 measured |
| LMArena Text: science | 1296 | 1508 | Kimi K3 |
| LMArena Text: medicine and healthcare | 1310 | 1489 | Kimi K3 |
| LMArena Text: legal and government | 1280 | 1503 | Kimi K3 |
| LMArena Text: business and finance | 1284 | 1470 | Kimi K3 |
| Neither model has a result on the other 3 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| Design Arena: websites | 852 | 1335 | Kimi K3 |
| Design Arena: UI components | Not measured | 1344 | Only Kimi K3 measured |
| Design Arena: game dev | Not measured | 1359 | Only Kimi K3 measured |
| Design Arena: data viz | 933 | 1351 | Kimi K3 |
| Design Arena: 3D | Not measured | 1388 | Only Kimi K3 measured |
| Design Arena: all code categories | Not measured | 1360 | Only Kimi K3 measured |
| Design Arena: SVG | Not measured | 1302 | Only Kimi K3 measured |
| LiveBench design | Not measured | 77.2% | Only Kimi K3 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index019
| Benchmark | gpt-oss-20b | Kimi K3 | Leader |
|---|---|---|---|
| Vals Index | Not measured | 53.0% | Only Kimi K3 measured |
| LiveBench data analysis | Not measured | 78.7% | Only Kimi K3 measured |
| Public Benefits Bench (Vals AI) | Not measured | 68.2% | Only Kimi K3 measured |
| SAGE (Vals AI) | Not measured | 52.8% | Only Kimi K3 measured |
| MedScribe (Vals AI) | Not measured | 88.0% | Only Kimi K3 measured |
| Vals Multimodal Index | Not measured | 73.4% | Only Kimi K3 measured |
| IFBench | 65.1% | Not measured | Only gpt-oss-20b measured |
| Long context reasoning (AA-LCR) | 34.7% | 88.7% | Kimi K3 |
| DTBench | 68.0% | 91.2% | Kimi K3 |
| LMCA | 14.5% | 52.7% | Kimi K3 |
| Surface Evolver Bench | Not measured | 95.0% | Only Kimi K3 measured |
| Furniture assembly | Not measured | 34.2% | Only Kimi K3 measured |
| LMArena Text | 1288 | 1476 | Kimi K3 |
| LMArena Text: instruction following | 1236 | 1485 | Kimi K3 |
| LMArena Text: creative writing | 1201 | 1457 | Kimi K3 |
| LMArena Text: English | 1303 | 1481 | Kimi K3 |
| LMArena Text: non-English | 1269 | 1466 | Kimi K3 |
| LMArena Text: Chinese | 1315 | 1529 | Kimi K3 |
| LMArena Text: German | 1255 | 1490 | Kimi K3 |
| LMArena Text: Japanese | 1244 | 1494 | Kimi K3 |
| LMArena Text: Korean | 1236 | 1460 | Kimi K3 |
| LMArena Text: French | Not measured | 1492 | Only Kimi K3 measured |
| LMArena Text: Spanish | 1267 | 1472 | Kimi K3 |
| LMArena Text: Russian | 1278 | 1485 | Kimi K3 |
| LMArena Text: Polish | 1252 | 1458 | Kimi K3 |
| LMArena Text: multi-turn | 1268 | 1489 | Kimi K3 |
| LMArena Text: longer queries | 1250 | 1494 | Kimi K3 |
| LMArena Text: writing and language | 1238 | 1471 | Kimi K3 |
| LMArena Text: entertainment and media | 1216 | 1453 | Kimi K3 |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | gpt-oss-20b | Kimi K3 | 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
gpt-oss-20b costs less
Repository review
50K input + 3K output tokens
gpt-oss-20b costs less
Agent loop
200K input + 10K output tokens
gpt-oss-20b 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 | OpenAI gpt-oss-20b | MoonshotAI Kimi K3 |
|---|---|---|
| Maker | OpenAI | Moonshot AI |
| Weights | Open weights | Open weights |
| Released | August 5, 2025 | July 16, 2026 |
| Context window | 131K | 1.05M |
| Input $/Mtok | $0.03 | $3.00 |
| Output $/Mtok | $0.15 | $15.00 |
| Coding index | Not benchmarked | 62.3 |
| Independent measurements behind it | 0 | 6 |
| Cost per solved task | Not computable | $0.81 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is gpt-oss-20b better than Kimi K3 for coding?
Only Kimi K3 has a coding score, 62.3 on the Vibe Coding Index; gpt-oss-20b has none, so the two cannot be ranked on coding. Pick gpt-oss-20b for output tokens 100.0x cheaper ($0.15 vs $15.00 per million).
Which is cheaper, gpt-oss-20b or Kimi K3?
gpt-oss-20b costs $0.03 per million input tokens and $0.15 per million output tokens; Kimi K3 costs $3.00 and $15.00. Cost per solved task is known for Kimi K3 only.
Which has the bigger context window, gpt-oss-20b or Kimi K3?
Kimi K3, with 1.05M tokens against 131K.
How many benchmarks is the gpt-oss-20b vs Kimi K3 comparison based on?
47 benchmarks have a result for both models as of October 21, 2026. gpt-oss-20b's coding index rests on 0 independent benchmarks and Kimi K3's on 6. Where only one model has a result, the page says so instead of naming a winner.