Tencent Releases Open-Source Hy4 LLM Preview With 770B Parameters and 1M+ Token Context

Tencent has released and open-sourced Hy4 preview, its latest large language model designed around coding, office productivity, and scientific research. The model features 770 billion total parameters, 49 billion active parameters, and a context window exceeding 1 million tokens. It is available globally through Tencent’s WorkBuddy, CodeBuddy, Yuanbao, and ima, while developers can also access it through APIs via Tencent Cloud TokenHub and OpenRouter.

Tencent Hy4 Preview Brings 770B Parameters and 1M+ Token Context

Hy4 preview represents a significant increase in model size, context length, and training data compared with its predecessors. Tencent says improvements across both pre-training and post-training have resulted in a major increase in overall intelligence, placing the model among the top tier of open-source models. Tencent also conducted an internal blind evaluation involving 163 experts and 203 engineering tasks. Hy4 preview recorded an average score of 2.99 out of 4.00, slightly ahead of GLM-5.3 at 2.92 and Kimi K3 at 2.94.

Built Around Real-World Productivity

Tencent developed Hy4 preview using training data created with its experts across areas including software engineering, gaming, finance, and security. The model was also co-designed with products such as WorkBuddy and CodeBuddy to improve its performance across practical workloads.

For software development, Hy4 preview is designed to handle long-context tasks involving code understanding, planning, debugging, and validation. It also improves the visual quality and interaction experience of front-end development, while office and analytical workloads benefit from capabilities for data analysis, financial analysis, and cross-document collaboration.

The model can also generate playable game prototypes from natural-language requests and work with game engines through multi-turn interactions. For scientific research, Tencent highlights improvements in areas such as AI research and development, molecular dynamics simulation, condensed-matter physics, and fundamental mathematics.

Hy4 Preview Helped Optimize Its Own Development

One of the more notable aspects of Hy4 preview is its involvement in parts of its own development process. Tencent says the model participated in automated optimization of training methods, data strategies, evaluation frameworks, and low-level operators by proposing approaches, running experiments, and using the resulting feedback in subsequent iterations.

Hy4 preview also analyzed bottlenecks in its inference system and performed multiple rounds of optimization involving operator fusion and communication. According to Tencent, these changes increased end-to-end throughput by 31.8% compared with the baseline across different context lengths and concurrency levels.

Free Access and API Pricing

Hy4 preview is available globally through WorkBuddy and CodeBuddy, as well as Tencent’s Yuanbao, ima, and other products. It can also be accessed through an API using Tencent Cloud TokenHub and OpenRouter, while free access through WorkBuddy and CodeBuddy is available for two weeks following launch.

Tencent lists API pricing at USD 0.834 per million input tokens, USD 2.501 per million output tokens, and USD 0.042 per million tokens for cache hits. Free access to Hy3 on WorkBuddy and CodeBuddy has also been extended until September 30.

The next batch of models in the Hy4 series is expected to roll out soon.

What is Tencent Hy4 preview?

Tencent Hy4 preview is a new large language model from Tencent that has been released as an open-source model. It is designed for real-world productivity workloads, including coding, office work, game development, and scientific research.

How many parameters does Tencent Hy4 preview have?

Tencent Hy4 preview has 770 billion total parameters, with 49 billion active parameters.

How large is the context window of Tencent Hy4 preview?

Hy4 preview has a context window of more than 1 million tokens. This allows the model to work with substantially larger amounts of contextual information for long-context tasks.

What can Tencent Hy4 preview be used for?

Hy4 preview is designed for coding, office productivity, data analysis, game development, and scientific research. Its software engineering capabilities include code understanding, planning, debugging, and validation for long-context development tasks.

Can Tencent Hy4 preview generate games?

Yes. According to Tencent, Hy4 preview can generate a playable game prototype from a single natural-language request and work with game engines. Developers can then continue refining projects through multi-turn interactions.

How did Tencent Hy4 preview perform in testing?

Tencent conducted an internal blind evaluation involving 163 experts and 203 engineering tasks. Hy4 preview received an average score of 2.99 out of 4.00, compared with 2.92 for GLM-5.3 and 2.94 for Kimi K3.

Did Tencent Hy4 preview help develop itself?

Tencent says Hy4 preview participated in the automated optimization of aspects of its own development, including training methods, data strategies, evaluation frameworks, and low-level operators. It also analyzed inference bottlenecks and helped optimize areas such as operator fusion and communication.

How much faster did Hy4 preview make its inference system?

Tencent reports that optimizations involving Hy4 preview increased end-to-end inference throughput by 31.8% compared with the baseline. The company says the gains were consistent across different context lengths and concurrency levels.

Where can I use Tencent Hy4 preview?

Hy4 preview is available globally through WorkBuddy, CodeBuddy, Yuanbao, and ima, as well as other Tencent products. Developers can also access the model through APIs via Tencent Cloud TokenHub and OpenRouter.

Is Tencent Hy4 preview free?

Hy4 preview is available for free on WorkBuddy and CodeBuddy for two weeks following its launch. Tencent has also extended free access to Hy3 on both platforms until September 30.

How much does the Tencent Hy4 preview API cost?

Tencent lists Hy4 preview API pricing at USD 0.834 per million input tokens, USD 2.501 per million output tokens, and USD 0.042 per million tokens for cache hits.

Is Tencent Hy4 preview open source?

Yes. Tencent has released Hy4 preview as an open-source model, making it available beyond Tencent’s own applications and API services.

Grant Soriano

PC Review Lead and Sales Officer at Gadget Pilipinas | Website

Grant is a Financial Management graduate from UST. His passion for gadgets and tech crossed him over in the industry where he could apply his knowledge as an enthusiast and in-depth analytic skills as a Finance Major. His passion allows him to earn at the same time help Gadget Pilipinas' readers in making smart, value-based decisions and purchases with his reviews and guides.