Model comparison
gpt-oss-20b vs Kimi K2.5 Instant
Kimi K2.5 Instant is the stronger model overall, scoring 42.9 to 32.1 on the Noometry Index.
Last verified . 15 shared benchmarks.
Summary
- They share 15 benchmarks with published results for both. gpt-oss-20b scores higher in 1 category and Kimi K2.5 Instant in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Kimi K2.5 Instant leads 60.8 to 35.8.
Side by side
| gpt-oss-20b | Kimi K2.5 Instant | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Noometry Index | 32.1 | 42.9 |
| Released | 2025-08-05 | — |
| Weights | Open | Open |
| Context window | 131K | — |
| Max output | 16K | — |
| Input $ / M tokens | $0.018 | — |
| Output $ / M tokens | $0.09 | — |
| Results tracked | 34 | 18 |
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Category by category
Coding Kimi K2.5 Instant leads
gpt-oss-20b: 37.1 (#185), Kimi K2.5 Instant: 42.3 (#95)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Coding | 1307 | 1483 |
| LMArena WebDev | — | 1404 |
| SciCode | 34.4% | — |
| WeirdML | 40.9% | — |
| ALE-Bench | 566.05 | — |
Agentic & Tool Use Not comparable
gpt-oss-20b: 9.2 (#146), Kimi K2.5 Instant: —
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| Terminal-Bench | 3.4% | — |
Reasoning Kimi K2.5 Instant leads
gpt-oss-20b: 18.8 (#251), Kimi K2.5 Instant: 28.5 (#88)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1274 | 1443 |
| Kagi LLM Benchmark | 53.2% | — |
| CritPt | 1.4% | — |
| Chess Puzzles | 4% | — |
| DTBench | 68% | — |
| LMCA | 14.5% | — |
| Epoch Capabilities Index | 137.81 | — |
Math gpt-oss-20b leads
gpt-oss-20b: 37.6 (#93), Kimi K2.5 Instant: 36.6 (#105)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Math | 1317 | 1443 |
| OTIS Mock AIME 2024-2025 | 65.3% | — |
| Omni-MATH | 56.5% | — |
Knowledge Kimi K2.5 Instant leads
gpt-oss-20b: 34.6 (#186), Kimi K2.5 Instant: 39.5 (#121)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Expert | 1258 | 1438 |
| GPQA Diamond | 60.8% | — |
| MMLU-Pro | 74% | — |
| GPQA (HELM) | 59.4% | — |
Multimodal Not comparable
gpt-oss-20b: —, Kimi K2.5 Instant: 39.5 (#47)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Vision | — | 1254 |
Multilingual Kimi K2.5 Instant leads
gpt-oss-20b: 42.4 (#192), Kimi K2.5 Instant: 52.2 (#89)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Non-English | 1269 | 1406 |
| LMArena Chinese | 1311 | 1450 |
| LMArena German | 1249 | 1413 |
| LMArena Korean | 1239 | 1378 |
| LMArena Russian | 1279 | 1404 |
| LMArena Spanish | 1267 | 1448 |
| LMArena French | — | 1403 |
| LMArena Japanese | 1245 | — |
Instruction Following Kimi K2.5 Instant leads
gpt-oss-20b: 62.0 (#235), Kimi K2.5 Instant: 75.5 (#61)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1236 | 1430 |
| IFEval | 73.2% | — |
Long Context Kimi K2.5 Instant leads
gpt-oss-20b: 37.9 (#203), Kimi K2.5 Instant: 43.8 (#82)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Longer Query | 1251 | 1435 |
Writing & Preference Kimi K2.5 Instant leads
gpt-oss-20b: 35.8 (#260), Kimi K2.5 Instant: 60.8 (#91)
| Benchmark | gpt-oss-20b | Kimi K2.5 Instant |
|---|---|---|
| LMArena Text | 1288 | 1420 |
| LMArena Creative Writing | 1201 | 1379 |
| LMArena Multi-Turn | 1268 | 1427 |
| EQ-Bench Creative Writing | 666 | — |
| WildBench | 73.7% | — |
Frequently asked questions
Is gpt-oss-20b better than Kimi K2.5 Instant?
Kimi K2.5 Instant is the stronger model overall, scoring 42.9 to 32.1 on the Noometry Index.
Is gpt-oss-20b or Kimi K2.5 Instant better for coding?
Kimi K2.5 Instant scores higher on coding benchmarks: 42.3 versus 37.1 in the Noometry coding category.
How many benchmarks do gpt-oss-20b and Kimi K2.5 Instant share?
15 benchmarks have published results for both models. gpt-oss-20b has 34 scored results on Noometry and Kimi K2.5 Instant has 18.