Model comparison
Qwen1.5 4b Chat vs Step 3.5 Flash
Step 3.5 Flash is the stronger model overall, scoring 41.7 to 28.3 on the Noometry Index.
Last verified . 13 shared benchmarks.
Alibaba (Qwen)
StepFunSummary
- They share 13 benchmarks with published results for both. Qwen1.5 4b Chat scores higher in 0 categories and Step 3.5 Flash in 8 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Step 3.5 Flash leads 59.0 to 23.9.
Side by side
| Qwen1.5 4b Chat | Step 3.5 Flash | |
|---|---|---|
| Provider | Alibaba (Qwen) | StepFun |
| Noometry Index | 28.3 | 41.7 |
| Released | — | 2026-01-29 |
| Weights | Open | Open |
| Context window | — | 256K |
| Max output | — | 256K |
| Input $ / M tokens | — | $0.10 |
| Output $ / M tokens | — | $0.30 |
| Results tracked | 13 | 19 |
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Category by category
Coding Step 3.5 Flash leads
Qwen1.5 4b Chat: 28.6 (#305), Step 3.5 Flash: 41.7 (#106)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Coding | 999 | 1436 |
Reasoning Step 3.5 Flash leads
Qwen1.5 4b Chat: 17.7 (#277), Step 3.5 Flash: 21.2 (#202)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Hard Prompts | 976 | 1411 |
| NYT Connections (extended) | — | 28.4% |
Math Step 3.5 Flash leads
Qwen1.5 4b Chat: 27.9 (#233), Step 3.5 Flash: 40.6 (#77)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Math | 1026 | 1408 |
| MathArena Final-Answer Competitions | — | 66.8% |
Knowledge Step 3.5 Flash leads
Qwen1.5 4b Chat: 26.2 (#252), Step 3.5 Flash: 39.0 (#127)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Expert | 980 | 1422 |
Multilingual Step 3.5 Flash leads
Qwen1.5 4b Chat: 24.2 (#285), Step 3.5 Flash: 50.7 (#115)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Non-English | 979 | 1386 |
| LMArena Chinese | 1024 | 1448 |
| LMArena German | 902 | 1404 |
| LMArena Russian | 952 | 1385 |
| LMArena French | — | 1421 |
| LMArena Japanese | — | 1353 |
| LMArena Korean | — | 1350 |
| LMArena Spanish | — | 1419 |
Instruction Following Step 3.5 Flash leads
Qwen1.5 4b Chat: 49.3 (#295), Step 3.5 Flash: 73.3 (#119)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | 979 | 1385 |
Long Context Step 3.5 Flash leads
Qwen1.5 4b Chat: 30.1 (#285), Step 3.5 Flash: 42.8 (#112)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Longer Query | 988 | 1402 |
Writing & Preference Step 3.5 Flash leads
Qwen1.5 4b Chat: 23.9 (#304), Step 3.5 Flash: 59.0 (#108)
| Benchmark | Qwen1.5 4b Chat | Step 3.5 Flash |
|---|---|---|
| LMArena Text | 997 | 1403 |
| LMArena Creative Writing | 969 | 1357 |
| LMArena Multi-Turn | 977 | 1405 |
Frequently asked questions
Is Qwen1.5 4b Chat better than Step 3.5 Flash?
Step 3.5 Flash is the stronger model overall, scoring 41.7 to 28.3 on the Noometry Index.
Is Qwen1.5 4b Chat or Step 3.5 Flash better for coding?
Step 3.5 Flash scores higher on coding benchmarks: 41.7 versus 28.6 in the Noometry coding category.
How many benchmarks do Qwen1.5 4b Chat and Step 3.5 Flash share?
13 benchmarks have published results for both models. Qwen1.5 4b Chat has 13 scored results on Noometry and Step 3.5 Flash has 19.