Model comparison
gpt-oss-120b vs Step 2 16k Exp 202412
Step 2 16k Exp 202412 is the stronger model overall, scoring 39.2 to 36.3 on the Noometry Index.
Last verified . 12 shared benchmarks.
StepFunSummary
- They share 12 benchmarks with published results for both. gpt-oss-120b scores higher in 4 categories and Step 2 16k Exp 202412 in 4 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where gpt-oss-120b leads 52.5 to 36.3.
- gpt-oss-120b has downloadable open weights; the other is API-only.
Side by side
| gpt-oss-120b | Step 2 16k Exp 202412 | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 36.3 | 39.2 |
| Released | 2025-08-05 | — |
| Weights | Open | Proprietary |
| Context window | 131K | — |
| Max output | 41K | — |
| Input $ / M tokens | $0.037 | — |
| Output $ / M tokens | $0.17 | — |
| Results tracked | 48 | 12 |
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Category by category
Coding Step 2 16k Exp 202412 leads
gpt-oss-120b: 33.5 (#256), Step 2 16k Exp 202412: 38.5 (#174)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Coding | 1380 | 1316 |
| SWE-bench Verified (bash only) | 26% | — |
| Aider Polyglot | 41.8% | — |
| SciCode | 36% | — |
| WeirdML | 48.2% | — |
| ALE-Bench | 575.62 | — |
| AlgoTune | 1.41 | — |
Agentic & Tool Use Not comparable
gpt-oss-120b: 12.2 (#153), Step 2 16k Exp 202412: —
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| Terminal-Bench | 18.7% | — |
| APEX-Agents | 4.4% | — |
| METR Time Horizons | 56.6% | — |
| Vending-Bench 2 | -21.53 | — |
Reasoning Step 2 16k Exp 202412 leads
gpt-oss-120b: 20.0 (#245), Step 2 16k Exp 202412: 25.9 (#142)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Hard Prompts | 1364 | 1299 |
| SimpleBench | 22.1% | — |
| Kagi LLM Benchmark | 58.6% | — |
| CritPt | 1.1% | — |
| Chess Puzzles | 20% | — |
| Mystery Game Puzzles | 2% | — |
| DTBench | 76.3% | — |
| LMCA | 22.1% | — |
| Surface Evolver Bench | 25% | — |
| Epoch Capabilities Index | 139.93 | — |
Math gpt-oss-120b leads
gpt-oss-120b: 52.5 (#50), Step 2 16k Exp 202412: 36.3 (#169)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Math | 1389 | 1304 |
| OTIS Mock AIME 2024-2025 | 88.9% | — |
| Omni-MATH | 68.8% | — |
Knowledge gpt-oss-120b leads
gpt-oss-120b: 42.4 (#96), Step 2 16k Exp 202412: 35.2 (#187)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Expert | 1356 | 1279 |
| GPQA Diamond | 75.8% | — |
| MMLU-Pro | 79.5% | — |
| Confabulations | 15.7% | — |
| Vectara Hallucination Rate | 14.2% | — |
| GPQA (HELM) | 68.4% | — |
Multilingual gpt-oss-120b leads
gpt-oss-120b: 48.0 (#147), Step 2 16k Exp 202412: 43.7 (#181)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Non-English | 1351 | 1290 |
| LMArena Chinese | 1385 | 1331 |
| LMArena Russian | 1343 | 1324 |
| LMArena French | 1369 | — |
| LMArena German | 1353 | — |
| LMArena Japanese | 1331 | — |
| LMArena Korean | 1282 | — |
| LMArena Spanish | 1389 | — |
Instruction Following gpt-oss-120b leads
gpt-oss-120b: 69.3 (#173), Step 2 16k Exp 202412: 67.9 (#192)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Instruction Following | 1318 | 1287 |
| IFEval | 83.6% | — |
Long Context Step 2 16k Exp 202412 leads
gpt-oss-120b: 31.4 (#278), Step 2 16k Exp 202412: 39.7 (#170)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Longer Query | 1319 | 1307 |
| Fiction.LiveBench | 44.4% | — |
Writing & Preference Step 2 16k Exp 202412 leads
gpt-oss-120b: 46.5 (#217), Step 2 16k Exp 202412: 52.3 (#173)
| Benchmark | gpt-oss-120b | Step 2 16k Exp 202412 |
|---|---|---|
| LMArena Text | 1365 | 1321 |
| LMArena Creative Writing | 1275 | 1328 |
| LMArena Multi-Turn | 1340 | 1292 |
| Short-Story Creative Writing | 77.1% | — |
| EQ-Bench Creative Writing | 961 | — |
| WildBench | 84.5% | — |
Frequently asked questions
Is gpt-oss-120b better than Step 2 16k Exp 202412?
Step 2 16k Exp 202412 is the stronger model overall, scoring 39.2 to 36.3 on the Noometry Index.
Is gpt-oss-120b or Step 2 16k Exp 202412 better for coding?
Step 2 16k Exp 202412 scores higher on coding benchmarks: 38.5 versus 33.5 in the Noometry coding category.
How many benchmarks do gpt-oss-120b and Step 2 16k Exp 202412 share?
12 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Step 2 16k Exp 202412 has 12.