StepFun · Released Sep 16, 2026Step 5 Preview
StepFun's next-generation flagship base model for coding and professional knowledge work, with native text, image, and video input and a 1M-token context window.
- Capability
- —No ECI score yet
- Input
- $1.00per 1M tokens
- Output
- $2.70per 1M tokens
- Context
- 1M1M max output
What it costs
- Input
- $1.00per million tokens
- Output
- $2.70per million tokens
- Cached input
- $0.05per million tokens
- Blended (3:1)
- $1.43pricier than 63% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $3.35 |
| Team assistant25M input + 5M output tokens | $38.50 |
| Production app250M input + 50M output tokens | $385.00 |
Official StepFun (Global) API price, as listed on models.dev.
Independent benchmarks
Epoch AI has not published a Capabilities Index score for Step 5 Preview yet.
The details
- Lab
- StepFun
- Released
- Sep 16, 2026
- Context window
- 1,000,000 tokens
- Max output
- 1,000,000 tokens
- Inputs
- Text, Images, Video
- Output
- Text
- Reasoning
- Adjustable effort low · medium · high
- Tool calling
- Yes
- Structured output
- Yes
- Weights
- Proprietary
- API model ID
step-5-previewon StepFun (Global)- Availability
- 7 API providerslisted on models.dev
More from StepFun
About Step 5 Preview
How much does Step 5 Preview cost?
Step 5 Preview costs $1.00 input / $2.70 output per million tokens (official StepFun (Global) API price). Cached input is $0.05 per million tokens. At a 3:1 input-to-output mix that is $1.43 per million tokens, more expensive than 63% of the 360 priced models we track.
What is the context window of Step 5 Preview?
Step 5 Preview accepts up to 1,000,000 tokens per request and can write up to 1,000,000 tokens in one response.
How good is Step 5 Preview?
Epoch AI has not published a Capabilities Index score for Step 5 Preview yet.
Is Step 5 Preview open source?
No. Step 5 Preview is proprietary; you use it through StepFun (Global)’s API or partner platforms.
What inputs does Step 5 Preview support?
Step 5 Preview accepts text, images and video and replies in text. It is a reasoning model with low, medium and high effort settings, supports tool calling and can return structured JSON output.
When was Step 5 Preview released?
StepFun released Step 5 Preview on Sep 16, 2026.
What are the best alternatives to Step 5 Preview?
The closest current models from other labs on capability, price and release date are LongCat-2.5-Preview (Meituan (LongCat), $0.75 / $2.95), Hy4 preview (Tencent, $0.834 / $2.50), Sakana Namazu (Sakana AI, $0.95 / $4.00) and MiMo-V2.5-Pro-UltraSpeed (Xiaomi, $1.30 / $2.61).