Model comparison
gpt-oss-20b vs Step 3
Step 3 is the stronger model overall, scoring 40.5 to 32.5 on the Noometry Index.
Last verified . 16 shared benchmarks.
StepFunSummary
- They share 16 benchmarks with published results for both. gpt-oss-20b scores higher in 1 category and Step 3 in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Step 3 leads 54.3 to 35.5.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 53.2% for gpt-oss-20b and 62.3% for Step 3.
Side by side
| gpt-oss-20b | Step 3 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 32.5 | 40.5 |
| 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 | 17 |
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Category by category
Coding Step 3 leads
gpt-oss-20b: 37.6 (#192), Step 3: 40.1 (#147)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Coding | 1306 | 1367 |
| SciCode | 34.4% | — |
| WeirdML | 40.9% | — |
| ALE-Bench | 566.05 | — |
Agentic & Tool Use Not comparable
gpt-oss-20b: 9.3 (#154), Step 3: —
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| Terminal-Bench | 3.4% | — |
Reasoning Step 3 leads
gpt-oss-20b: 19.3 (#261), Step 3: 28.4 (#105)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| Kagi LLM Benchmark | 53.2% | 62.3% |
| LMArena Hard Prompts | 1274 | 1355 |
| CritPt | 1.4% | — |
| Chess Puzzles | 4% | — |
| DTBench | 68% | — |
| LMCA | 14.5% | — |
| Epoch Capabilities Index | 137.82 | — |
Math gpt-oss-20b leads
gpt-oss-20b: 39.4 (#103), Step 3: 37.6 (#148)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Math | 1317 | 1366 |
| OTIS Mock AIME 2024-2025 | 65.3% | — |
| Omni-MATH | 56.5% | — |
Knowledge Step 3 leads
gpt-oss-20b: 34.6 (#195), Step 3: 36.8 (#164)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Expert | 1258 | 1333 |
| GPQA Diamond | 60.8% | — |
| MMLU-Pro | 74% | — |
| GPQA (HELM) | 59.4% | — |
Multimodal Not comparable
gpt-oss-20b: —, Step 3: 35.5 (#86)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Vision | — | 1177 |
Multilingual Step 3 leads
gpt-oss-20b: 42.2 (#197), Step 3: 46.3 (#159)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Non-English | 1268 | 1327 |
| LMArena Chinese | 1314 | 1397 |
| LMArena German | 1255 | 1371 |
| LMArena Korean | 1236 | 1269 |
| LMArena Russian | 1278 | 1331 |
| LMArena Spanish | 1267 | 1371 |
| LMArena Japanese | 1244 | — |
Instruction Following Step 3 leads
gpt-oss-20b: 61.8 (#240), Step 3: 70.4 (#164)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Instruction Following | 1236 | 1332 |
| IFEval | 73.2% | — |
Long Context Step 3 leads
gpt-oss-20b: 37.9 (#209), Step 3: 40.3 (#157)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Longer Query | 1250 | 1326 |
Writing & Preference Step 3 leads
gpt-oss-20b: 35.5 (#265), Step 3: 54.3 (#151)
| Benchmark | gpt-oss-20b | Step 3 |
|---|---|---|
| LMArena Text | 1287 | 1350 |
| LMArena Creative Writing | 1201 | 1321 |
| LMArena Multi-Turn | 1268 | 1341 |
| EQ-Bench Creative Writing | 666 | — |
| WildBench | 73.7% | — |
Frequently asked questions
Is gpt-oss-20b better than Step 3?
Step 3 is the stronger model overall, scoring 40.5 to 32.5 on the Noometry Index.
Is gpt-oss-20b or Step 3 better for coding?
Step 3 scores higher on coding benchmarks: 40.1 versus 37.6 in the Noometry coding category.
How many benchmarks do gpt-oss-20b and Step 3 share?
16 benchmarks have published results for both models. gpt-oss-20b has 34 scored results on Noometry and Step 3 has 17.