Unverified50% confidenceReleaseExact time
StepFun has open-sourced the Step5 preview model, with 600 billion total parameters, only 27 billion parameters activated per token, and a context window supporting up to 1 million tokens.
1
Sources
50%
Confidence
Short-term (~14 days)
Relevance
10/18/2026
First Seen
Valid until: 11/1/2026
Sources
DeepSeek and StepFun Open-Source on the Same Day, While Websites Shut Out AI Agents
bilibiliSKC智能知识管理系统10/18/2026
Related Entities
Related Claims
UnverifiedStepFun's Step 5 Preview has launched on the WorkBuddy platform and is free for a limited time, with a parameter scale of 600 billion, 27 billion activated, and support for a 1 million context.72% similarVerifiedThe context window of Gemini 1.5 Pro has been extended to 1 million tokens, equivalent to approximately 750,000 English words.70% similar
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