Step 5 Preview

Closed Source

Closed Weights

Parameters

600B (Estimated)

Context Length

Modality

Multimodal

Architecture

Undisclosed

License

Proprietary

Release Date

8 Oct 2026

Knowledge Cutoff

API Pricing (per 1M)

Input: $1.00 · Output: $2.70

Evaluation Benchmarks

Rank

#44

Benchmark	Score	Rank
Intelligence Index Artificial Analysis	0.44	31
Web Development WebDev Arena	high 1564	34
Agent Arena Agent Arena	0.01	36
General Text Text Arena	1447	68

Rankings

Overall Rank

#44

Coding Rank

#49

About Step 5 Preview

Step 5 Preview is StepFun's flagship multimodal agentic model built on a sparse Mixture-of-Experts architecture with 27B active and 600B total parameters. It is tailored for complex agentic workflows, software engineering, and professional reasoning tasks.

Technical Specifications

Architecture specifications are undisclosed for proprietary models.

About Step 5

The Step 5 model family developed by StepFun.

Other Step 5 Models

No related models available