Step 5 Preview

Eesel AI provides an analysis of Step 5 Preview as StepFun's (阶跃星辰) new flagship model for complex work and agentic tasks, with emphasis on software engineering and finance. The article explains the sparse MoE design at 600B total / 27B active parameters, detailing how the router selects a small subset of expert su The piece surfaces StepFun's vendor chart claim of 65% lower cost than GLM-5.3 and Kimi K3 at comparable intelligence, flagging it as a pitch rather than an independent verdict. It contextualizes Step 5 Preview within the broader Step model family and notes StepFun's existing open-weights footprint on Hugging Face, whi

There's An AI For That describes Step 5 Preview as StepFun's newest flagship model announced September 20, 2026, built on a sparse MoE architecture with 600B total / 27B active parameters arranged across 92 transformer layers in a narrow-deep configuration. It supports a 1M-token context window for both input and outpu The listing documents capability for long-horizon agentic work, including coordinating hundreds of sequential tool calls (around 950 web fetches) within a single agent run, and cites benchmark performance on FrontierFinance, DRACO, DeepSWE v1.1, and ProgramBench. API access is reported at $1.00 per million input tokens

MarkTechPost reports on StepFun's release of Step 5 Preview, confirming the model's positioning as a flagship for agentic work targeting software engineering, professional knowledge work, and finance, with the launch centered on a cost-efficiency Pareto frontier framing rather than raw leaderboard claims. The article c The article lists canonical specifications including model ID step-5-preview, a 1M-token context window, text/image/video input with text output, and reasoning effort options of low, medium, and high, alongside streaming, tool calling, JSON Mode, JSON Schema, and prompt caching support. It highlights the sparse MoE des

AIbase reports on Step 5 Preview as StepFun's new flagship base model positioned for real-world Agentic tasks, built on a sparse MoE architecture with 600B total parameters, 27B active per token, native support for up to a 1M-token context window, and direct processing of text and visual inputs. The article notes an Ar It highlights that single-task cost is reported at roughly one-eighth of Claude Opus 5, with strong benchmark showings on ALE-CLI, FrontierFinance, DRACO, and GDPval-AA v2 (using Artificial Analysis results as of September 19). The piece also covers StepFun's StepCodeBench spanning 553 independent code repositories, 9

ExplainX provides a detailed third-party analysis of Step 5 Preview's "Advancing the Pareto Frontier" launch on September 20, 2026, contextualizing the claim within Artificial Analysis methodology. The article confirms the 600B total / 27B active sparse MoE architecture, 1M-token context with vision support, and the he The piece notes that Step 5 Preview does not beat GPT-6 Astra or Claude Opus 5 outright on the Intelligence Index, with those models remaining higher at much higher per-task cost, and that open weights are promised for October 15, 2026. It positions Step 5 Preview next to GLM-5.3, Kimi K3, and DeepSeek V4, with current

StepFun's official product page introduces Step 5 Preview as a new flagship model for agentic work, built on a sparse Mixture-of-Experts architecture with 600B total parameters, 27B active per token, a 1M-token context window, and vision input. The page frames the model as advancing the Pareto frontier between intellig The supplied excerpt includes StepFun's vendor benchmark tables covering DeepSWE v1.1, StepCodeBench, ProgramBench, Terminal-Bench v4, Agents' Last Exam (ALE-CLI), GDPval-AA v2.1, FrontierFinance, and DRACO, comparing Step 5 Preview (High) against Kimi K3, GLM-5.3, GPT-6 Astra, and Claude Opus 5. Methodology notes spec