Step 3.5 Flash 2603
by StepFunChat
StepFun flash model for efficient multimodal reasoning, coding, and tool use
- Context
- 256K tokens
- Max output
- 256,000 tokens
- Released
- 2026-04-02
- Weights
- Open
stepfun/step-3-5-flash-2603 · also seen as stepfun-ai/step-3.5-flash-2603
Specifications
Full facts as recorded, incl. what is unknown.
- Released
- 2026-04-02
- Weights
- Open
- Input
- Text
- Output
- Text
- Context window
- 256,000 max across endpoints
- Max output
- 256,000
- Providers
- 5 + 1 gateway, not counted as providers
- Epoch Capabilities Index
- not evaluated
- Direct price range
- $0.10 in · $0.30 out per 1M tokens · 3 of 5 providers have a comparable price
More details
- Last updated
- 2026-04-02
- Knowledge cutoff
- 2025-01
Capabilities
Across all endpoints: supported if any endpoint supports it.
- Tool calling
- Parallel toolsunknown
- Structured output
- Reasoning
- Image input
- PDF input
- Audio input
- Audio outputunknown
- Video input
- Prompt cachingunknown
- Web searchunknown
- Computer useunknown
- System messagesunknown
- Assistant prefillunknown
- Temperature
- Streamingunknown
- Attachments
Endpoints
One row per provider and variant; gateways are listed separately.
Loading endpoints…
Price history
No change since 19 Oct 2026. The cheapest direct price has been $0.10 in / $0.30 out per 1M tokens at StepFun (China) on every data refresh since then.
Tracked from 19 Oct 2026. Headline-eligible direct prices only, so a price the sanity check flags never draws a spike. Series as JSON
Cost calculator
Loading endpoints…
Similarly priced models
Blended rate per 1M tokens, each at its own cheapest provider (10M input : 2M output mix).
| Model | Blended/1M | In/1M | Out/1M | Context | vs Step 3.5 Flash 2603 |
|---|---|---|---|---|---|
| Gemma 4 31B Split-UntiedGoogle | $0.133 | $0.10 | $0.30 | 262K | +0% |
| Manta Pro 1.0MegaNova AI | $0.133 | $0.06 | $0.50 | 65.5K | +0% |
| Devstral Small 2Mistral AI | $0.133 | $0.10 | $0.30 | 256K | +0% |
| Mistral Small 3.1 24BMistral AI | $0.133 | $0.10 | $0.30 | 131K | +0% |
| Voxtral SmallMistral AI | $0.133 | $0.10 | $0.30 | 32.8K | +0% |
| Voxtral Small 24B 2507Mistral AI | $0.133 | $0.10 | $0.30 | 32.8K | +0% |
| MiMo-V2.5Xiaomi | $0.133 | $0.08 | $0.40 | 1.05M | +0% |
| MiMo-V2-FlashXiaomi | $0.133 | $0.10 | $0.30 | 262K | +0% |
More from StepFun
Newest StepFun models in the catalogue. All StepFun models
| Model | Released | Context | Listed price |
|---|---|---|---|
| Step 5 Preview | 2026-09-16 | 1M | from $0.959 |
| Step 3.7 Flash | 2026-05-29 | 256K | from $0.185 |
| StepAudio 2.5 ASR | 2026-04-24 | — | unpriced |
| StepAudio 2.5 TTS | 2026-04-16 | — | unpriced |
| Step TTS 2 | 2026-03-01 | — | unpriced |
| Step 3.5 Flash | 2026-01-29 | 256K | from $0.09 |
| Gelab Zero 4b Preview | 2025-12-23 | 8.2K | unpriced |
| Step-3 | 2025-07-31 | 65.5K | unpriced |