Model comparison
Step 2 16k Exp 202412 vs Step 3.5 Flash
Step 3.5 Flash is the stronger model overall, scoring 41.7 to 38.6 on the Noometry Index.
Last verified . 12 shared benchmarks.
StepFunSummary
- They share 12 benchmarks with published results for both. Step 2 16k Exp 202412 scores higher in 1 category and Step 3.5 Flash in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Step 3.5 Flash leads 40.6 to 33.6.
- Step 3.5 Flash has downloadable open weights; the other is API-only.
Side by side
| Step 2 16k Exp 202412 | Step 3.5 Flash | |
|---|---|---|
| Provider | StepFun | StepFun |
| Noometry Index | 38.6 | 41.7 |
| Released | — | 2026-01-29 |
| Weights | Proprietary | Open |
| Context window | — | 256K |
| Max output | — | 256K |
| Input $ / M tokens | — | $0.10 |
| Output $ / M tokens | — | $0.30 |
| Results tracked | 12 | 19 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Step 3.5 Flash leads
Step 2 16k Exp 202412: 37.9 (#170), Step 3.5 Flash: 41.7 (#106)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Coding | 1316 | 1436 |
Reasoning Step 2 16k Exp 202412 leads
Step 2 16k Exp 202412: 24.8 (#140), Step 3.5 Flash: 21.2 (#202)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Hard Prompts | 1299 | 1411 |
| NYT Connections (extended) | — | 28.4% |
Math Step 3.5 Flash leads
Step 2 16k Exp 202412: 33.6 (#171), Step 3.5 Flash: 40.6 (#77)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Math | 1305 | 1408 |
| MathArena Final-Answer Competitions | — | 66.8% |
Knowledge Step 3.5 Flash leads
Step 2 16k Exp 202412: 34.6 (#187), Step 3.5 Flash: 39.0 (#127)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Expert | 1279 | 1422 |
Multilingual Step 3.5 Flash leads
Step 2 16k Exp 202412: 43.9 (#176), Step 3.5 Flash: 50.7 (#115)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Non-English | 1290 | 1386 |
| LMArena Chinese | 1331 | 1448 |
| LMArena Russian | 1324 | 1385 |
| LMArena French | — | 1421 |
| LMArena German | — | 1404 |
| LMArena Japanese | — | 1353 |
| LMArena Korean | — | 1350 |
| LMArena Spanish | — | 1419 |
Instruction Following Step 3.5 Flash leads
Step 2 16k Exp 202412: 68.1 (#187), Step 3.5 Flash: 73.3 (#119)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | 1287 | 1385 |
Long Context Step 3.5 Flash leads
Step 2 16k Exp 202412: 39.7 (#165), Step 3.5 Flash: 42.8 (#112)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Longer Query | 1307 | 1402 |
Writing & Preference Step 3.5 Flash leads
Step 2 16k Exp 202412: 52.5 (#168), Step 3.5 Flash: 59.0 (#108)
| Benchmark | Step 2 16k Exp 202412 | Step 3.5 Flash |
|---|---|---|
| LMArena Text | 1321 | 1403 |
| LMArena Creative Writing | 1328 | 1357 |
| LMArena Multi-Turn | 1292 | 1405 |
Frequently asked questions
Is Step 2 16k Exp 202412 better than Step 3.5 Flash?
Step 3.5 Flash is the stronger model overall, scoring 41.7 to 38.6 on the Noometry Index.
Is Step 2 16k Exp 202412 or Step 3.5 Flash better for coding?
Step 3.5 Flash scores higher on coding benchmarks: 41.7 versus 37.9 in the Noometry coding category.
How many benchmarks do Step 2 16k Exp 202412 and Step 3.5 Flash share?
12 benchmarks have published results for both models. Step 2 16k Exp 202412 has 12 scored results on Noometry and Step 3.5 Flash has 19.