295B total / 21B active (MoE) + 3.8B MTP layer
256K tokens (262,144)
Tencent Hy Community License Agreement
Officially open-sourced on April 23, 2026, Hy3-preview is positioned by Tencent as their strongest shipped model so far and the first trained on a rebuilt infrastructure. Release materials emphasize major gains in complex reasoning, instruction following, context learning, coding, and agent tasks, with strongest claimed improvements in Code & Agent benchmarks (including SWE-bench Verified, Terminal-Bench 2.0, BrowseComp, and WideSearch). The model card describes a large MoE architecture and notes deployable chat-completions usage with reasoning-effort controls (no_think/low/high), while also releasing a paired pre-trained Base checkpoint under the same release.