SpaceXAI vs 
StepFun
Verdict
- SpaceXAI's flagship leads: Grok 4.6 at 66.0 vs Step 5 Preview at 64.9.
- SpaceXAI's fastest ranked model (Grok 4.20 Multi-Agent, 304 tok/s) beats StepFun's (Step 3.7 Flash, 195 tok/s).
- StepFun publishes more open-weights models (3 vs 1).
- SpaceXAI ships more often: one model every 42 days against every 406.
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 | – | Step 3.5 Flash 54.6$0.150/M |
| Under $2/M | Grok 4.20 thinking 59.9$1.56/M | Step 5 Preview 64.9$1.43/M |
| Under $10/M | Grok 4.6 medium 66.0$3.00/M | Step 5 Preview 64.9$1.43/M |
| Any price | Grok 4.6 medium 66.0$3.00/M | Step 5 Preview 64.9$1.43/M |
Line-up
| Metric | SpaceXAI | StepFun |
|---|---|---|
| Flagship index | 66.0 | 64.9 |
| Ranked models | 16 | 6 |
| Open-weights models | 1 | 3 |
| Cheapest ranked, $/M | $1.25 | $0.150 |
| Fastest ranked, tok/s | 304 | 195 |
| Release cadence, days | 42 | 406 |
| Last release | 21 Sept 2026 | 29 May 2026 |
| Next expected | 16 Oct 2026 – 18 Nov 2026 | 27 Jan 2027 – 18 Dec 2027 |