OpenAI vs 
StepFun
Verdict
- OpenAI's flagship leads: GPT-6 Astra at 70.4 vs Step 5 Preview at 60.5.
- OpenAI has the better model in 3 of 4 price bands.
- OpenAI's fastest ranked model (GPT-5.4 Mini, 255 tok/s) beats StepFun's (Step 5 Preview, 229 tok/s).
- StepFun publishes more open-weights models (5 vs 3).
- OpenAI ships more often: one model every 22 days against every 59.
Best model per price band
Each provider’s highest-index model below the price ceiling. Purple marks the winner of the band.
| Price band | OpenAI | StepFun |
|---|---|---|
| Under $0.50/M | GPT-6 Luna max 60.0$0.200/M | Step 3.5 Flash 53.7$0.150/M |
| Under $2/M | GPT-6 Luna max 60.0$0.200/M | Step 5 Preview 60.5$1.43/M |
| Under $10/M | GPT-6.1 Sol max 69.9$4.00/M | Step 5 Preview 60.5$1.43/M |
| Any price | GPT-6 Astra max 70.4$20.00/M | Step 5 Preview 60.5$1.43/M |
Line-up
| Metric | OpenAI | StepFun |
|---|---|---|
| Flagship index | 70.4 | 60.5 |
| Ranked models | 44 | 7 |
| Open-weights models | 3 | 5 |
| Cheapest ranked, $/M | $0.093 | $0.150 |
| Fastest ranked, tok/s | 255 | 229 |
| Release cadence, days | 22 | 59 |
| Last release | 29 Sept 2026 | 18 Sept 2026 |
| Next expected | 12 Oct 2026 – 29 Oct 2026 | 23 Oct 2026 – 9 Dec 2026 |