Model comparison
o3-pro vs Step 3.7 Flash
o3-pro is the stronger model overall, scoring 42.9 to 37.3 on the Noometry Index. Step 3.7 Flash costs 84× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.
Last verified . 0 shared benchmarks.
StepFunSummary
- The widest gap is in coding, where o3-pro leads 55.5 to 40.0.
- Step 3.7 Flash is cheaper at $0.18 / $1.11 per million input/output tokens, against $20 / $80 for o3-pro.
- Step 3.7 Flash accepts more context: 256K tokens versus 200K.
- Step 3.7 Flash has downloadable open weights; the other is API-only.
Side by side
| o3-pro | Step 3.7 Flash | |
|---|---|---|
| Provider | OpenAI | StepFun |
| Noometry Index | 42.9 | 37.3 |
| Released | 2025-06-10 | 2026-05-29 |
| Weights | Proprietary | Open |
| Context window | 200K | 256K |
| Max output | 100K | 256K |
| Input $ / M tokens | $20 | $0.18 |
| Output $ / M tokens | $80 | $1.11 |
| Results tracked | 12 | 5 |
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Category by category
Coding o3-pro leads
o3-pro: 55.5 (#24), Step 3.7 Flash: 40.0 (#150)
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| Aider Polyglot | 84.9% | — |
| SciCode | — | 40% |
| WeirdML | 58.2% | — |
| ALE-Bench | — | 694.12 |
Reasoning o3-pro leads
o3-pro: 23.8 (#171), Step 3.7 Flash: 21.6 (#219)
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| ARC-AGI-2 | 4.9% | — |
| Kagi LLM Benchmark | 72.1% | — |
| NYT Connections (extended) | — | 39.7% |
| ARC-AGI-1 | 59.3% | — |
| CritPt | — | 2.3% |
| DTBench | 86.9% | — |
| LMCA | 38.5% | — |
| Epoch Capabilities Index | 147.42 | — |
Math Not comparable
o3-pro: —, Step 3.7 Flash: 42.9 (#82)
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| MathArena Final-Answer Competitions | — | 68.5% |
Knowledge Not comparable
o3-pro: 29.5 (#238), Step 3.7 Flash: —
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| Confabulations | 14.2% | — |
| Vectara Hallucination Rate | 23.3% | — |
Long Context Not comparable
o3-pro: 72.2 (#1), Step 3.7 Flash: —
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| Fiction.LiveBench | 97.2% | — |
Writing & Preference Not comparable
o3-pro: 57.1 (#133), Step 3.7 Flash: —
| Benchmark | o3-pro | Step 3.7 Flash |
|---|---|---|
| Short-Story Creative Writing | 84.4% | — |
Frequently asked questions
Is o3-pro better than Step 3.7 Flash?
o3-pro is the stronger model overall, scoring 42.9 to 37.3 on the Noometry Index. Step 3.7 Flash costs 84× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.
Which is cheaper, o3-pro or Step 3.7 Flash?
Step 3.7 Flash is cheaper. It lists at $0.18 per million input tokens and $1.11 per million output tokens; o3-pro lists at $20 and $80.
Is o3-pro or Step 3.7 Flash better for coding?
o3-pro scores higher on coding benchmarks: 55.5 versus 40.0 in the Noometry coding category.
Which has the bigger context window?
Step 3.7 Flash does, with 256K tokens against 200K.
How many benchmarks do o3-pro and Step 3.7 Flash share?
0 benchmarks have published results for both models. o3-pro has 12 scored results on Noometry and Step 3.7 Flash has 5.