Major Release StepFun · Released
Step 3.5 Flash 2603
What is Step 3.5 Flash 2603?
Step 3.5 Flash 2603 is a Major Release AI model from StepFun, released on April 2, 2026. It has a 256K tokens context window, costs $0.00 per million input tokens, and scores 1393 on Chatbot Arena Elo. It is available via the company's API.
StepFun Step 3.5 Flash 2603 — AA Intelligence Index 38.5, 256K tokens context, reasoning model.
How much does Step 3.5 Flash 2603 cost?
| Metric | Price |
|---|---|
| input per mtok | $0.00 |
| output per mtok | $0.00 |
Pricing data verified .
What context window does Step 3.5 Flash 2603 have?
- Context window
- 256K tokens
- Max output
- 256K
- Input modalities
- text
- Output modalities
- text
How does Step 3.5 Flash 2603 score on benchmarks?
| Benchmark | Score |
|---|---|
| GPQA Diamond | 82.6% |
| HLE | 22.6% |
| SciCode | 38.5% |
| TAU2-bench | 87.4% |
| TerminalBench-Hard | 32.6% |
| IF-Bench | 66.5% |
| LiveCodeBench Reasoning | 54.3% |
| AA Intelligence Index | 38.5 |
| Chatbot Arena Elo | 1393 |
Benchmark scores verified .