Tencent open-sources 770B-parameter Hy4 AI model

Tencent has released Hy4 preview, an open-source artificial intelligence model with 770 billion parameters, marking the Chinese tech giant's latest move in an intensifying global AI race. The model became available over the weekend through public repositories, Tencent Cloud, and OpenRouter.opensourceforu+1

A Massive but Efficient Architecture

Built on a mixture-of-experts architecture, Hy4 preview activates only 49 billion of its 770 billion parameters for any given text request, keeping computational costs manageable despite the model's scale. It features a one-million-token context window, allowing it to process vast amounts of text in a single session — a capability Tencent is positioning for extended coding projects, document-heavy office work, game development, and scientific research.thedailystar+1

Tencent describes the model as its most capable yet, claiming the largest generation-over-generation improvement in its AI lineup. In a blind internal evaluation, 163 Tencent experts scored Hy4 preview at 2.99 out of a possible range across 203 engineering tasks, edging out rival Chinese models GLM 5.3 (2.92) and Kimi K3 (2.94). The company trained the model using work-related data drawn from its own software engineers, game developers, finance analysts, and security experts.opensourceforu

Practical Applications and Limitations

Tencent is targeting several practical use cases. The company says Hy4 preview can handle long-horizon software engineering sessions — understanding, planning, debugging, and verifying work across extended interactions. It can also convert scattered files into structured documents, spreadsheets, and presentations, and reportedly generated playable game prototypes from single prompts.opensourceforu

For more autonomous workflows, Tencent says the model managed several parallel Codex sessions, adjusting its research direction as results arrived. In a small-model post-training task, it reportedly outperformed independently operating Codex instances across all eight benchmarks.opensourceforu

Tencent plans to integrate Hy4 into its CodeBuddy and WorkBuddy products. The company acknowledged that this early version can "over-reason and over-verify complex tasks," sometimes taking longer than necessary or repeatedly checking its own answers.thedailystar+1

A Crowded Field

The release comes amid fierce competition among Chinese and global AI developers. Tencent's decision to open-source a model of this scale follows a pattern set by rivals including Alibaba and DeepSeek, as companies vie for developer adoption and ecosystem influence. The open-source approach allows external developers to build on the model, potentially accelerating its refinement beyond what Tencent's internal teams could achieve alone.thedailystar