Step 5 Preview

Open weights Preview Multimodal MoE step-5-preview

600B MoE flagship (27B active) with 1M context and image/video input; weights published 2026-10-15.

Released
Sep 20, 2026
Context window
1M tokens
Max output
65.5K tokens
Parameters
600B 27B active
Input price
$1.00 per 1M
Output price
$2.70 per 1M

Prices are first-party list prices in USD at the standard tier. Last verified Oct 30, 2026.

Pricing

Launch priceSep 20, 2026
$1.00 in / $2.70 out
Current price since Sep 20, 2026
$1.00 in / $2.70 out
Cached input $0.10 per 1M

Specifications

Developer
StepFun
Model type
Multimodal
Architecture
MoE
Parameters
600B (27B active)
Input
Text Image Video
Output
Text
Knowledge cutoff
Not disclosed
License
Custom open license
API access
First-party API
Capabilities
Agentic Coding Flagship Long context Reasoning Tool use Vision