Grok 4.20 0309 vs Step 3.5 Flash 2603
xAI vs StepFun — benchmarks, pricing, and capabilities side by side.
- •Grok 4.20 0309 has the higher intelligence index (88.5 vs 82.6)
- •Step 3.5 Flash 2603 is cheaper ($0.00 vs $2.00 per 1M input)
- •Step 3.5 Flash 2603 is faster
| Grok 4.20 0309 | Step 3.5 Flash 2603 | |
|---|---|---|
| Intelligence index | 88.5 | 82.6 |
| Developer | xAI | StepFun |
| Type | LLM | LLM |
| Access | — | — |
| Context window | — | — |
| Input price | $2.00 / 1M | $0.00 / 1M |
| Output price | $6.00 / 1M | $0.00 / 1M |
| Speed | 97 tok/s | 197 tok/s |
| Released | March 10, 2026 | April 2, 2026 |
| Parameters | — | — |
| Input modalities | — | — |
| Output modalities | — | — |
Shared benchmarks
Grok 4.20 0309
Step 3.5 Flash 2603
GPQA Diamond
88.5
82.6
Humanity’s Last Exam
30
22.6