StepFun: Step3
By Stepfun Ai
Released: 2025-08-28
Stepfun AI Step3 features 38B parameters, MoE architecture and 66k-token context window. Step3 is a cutting-edge multimodal reasoning model—built on a Mixture-of-Experts architecture with 321B total parameters and 38B active. It is designed end-to-end to minimize decoding costs while delivering top-tier performance in vision–language reasoning. Through the co-design of Multi-Matrix Factorization Attention (MFA) and Attention-FFN Disaggregation (AFD), Step3 maintains exceptional efficiency across both flagship and low-end accelerators. Premium pricing at $0.57/1M tokens reflects its advanced capabilities.
Visit StepFun: Step3AI-Powered
Leverages advanced AI technology to deliver cutting-edge capabilities and results.
Fast & Efficient
Optimized performance ensures quick results without compromising on quality.
Purpose-Built
Specifically designed for llms tasks and workflows.
Stepfun Ai Model Timeline
66k tokens context
Specifications
AI Evaluation
Optimized for programming tasks, this model excels at code generation, debugging, and software engineering workflows with solid benchmark performance.
Pros
- Strong code generation and debugging
- Advanced logical reasoning
- Image and visual analysis
- Multi-modal input support
Cons
- Moderate API costs
- May lack creative flair
Related Tools
FLUX
FLUX, from Black Forest Labs, is a family of high-quality open and commercial image generation models prized for photorealism and prompt adherence. Widely integrated across third-party tools and APIs, it has become a default backbone for image generation.
Claude Opus 4.8
Claude Opus 4.8 is Anthropic's June 2026 flagship model, succeeding Opus 4.7. It posts a headline score of 81 on the hardest agentic coding and reasoning suites, holds long-horizon tool-use plans together across far more steps, and is notably more candid about its own uncertainty - refusing to fabricate rather than confidently pressing on. It is the default choice for serious agentic and software-engineering workloads.
Anthropic Mythos 1
Mythos 1 is the full release of Anthropic's specialised, security-focused system, graduating from the guarded Claude Mythos Preview. Built around Project Glasswing, it pairs frontier reasoning with defensive security tooling - vulnerability analysis, triage and incident response - deployed with heavy oversight and auditability. It runs alongside the general-purpose Claude family rather than replacing it.