SpaceXAI vs 
StepFun
Verdict
- SpaceXAI's flagship leads: Grok 4.6 at 60.5 vs Step 3.5 Flash at 56.4.
- SpaceXAI has the better model in 3 of 4 price bands.
- SpaceXAI's fastest ranked model (Grok 4.20 Multi-Agent, 347 tok/s) beats StepFun's (Step 5 Preview, 132 tok/s).
- StepFun publishes more open-weights models (5 vs 1).
- SpaceXAI ships more often: one model every 41 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 | SpaceXAI | StepFun |
|---|---|---|
| Under $0.50/M | Grok 4.1 Fast thinking 55.6$0.275/M | Step 3.5 Flash 56.4$0.150/M |
| Under $2/M | Grok 4.20 thinking 58.4$1.56/M | Step 3.5 Flash 56.4$0.150/M |
| Under $10/M | Grok 4.6 high 60.5$3.00/M | Step 3.5 Flash 56.4$0.150/M |
| Any price | Grok 4.6 high 60.5$3.00/M | Step 3.5 Flash 56.4$0.150/M |
Line-up
| Metric | SpaceXAI | StepFun |
|---|---|---|
| Flagship index | 60.5 | 56.4 |
| Ranked models | 15 | 5 |
| Open-weights models | 1 | 5 |
| Cheapest ranked, $/M | $0.275 | $0.150 |
| Fastest ranked, tok/s | 347 | 132 |
| Release cadence, days | 41 | 59 |
| Last release | 21 Sep 2026 | 18 Sep 2026 |
| Next expected | 15 Oct 2026 – 17 Nov 2026 | 23 Oct 2026 – 9 Dec 2026 |