# TestingCatalog — Tencent released open-source Hy4 preview model

- Company: TestingCatalog (testingcatalog.com)
- Announced: 2026-08-29T12:32:00+00:00
- Category: open-weight-release
- Coverage: not counted
- Announcement: yes
- Group: models
- Source: https://www.testingcatalog.com/tencent-released-open-source-hy4-preview-model/
- Record: https://forck.live/items/8902-tencent-released-open-source-hy4-preview-model
- Subject: AI models / agents / unreleased features
- Open weights: yes
- Models affected: Hy4 preview
- Context window: one-million-token context window
- Pricing: API pricing per million tokens is $0.042 for cached input, $0.834 for input, and $2.501 for output.

Tencent released the open-source Hy4 preview model, a 770-billion-parameter flagship with 49 billion active parameters and a one-million-token context window. The model targets long-horizon software engineering, document-heavy office work, game development and scientific research, and received positive internal comparison results against GLM 5.3 and Kimi K3.

## Evidence

Verbatim from https://www.testingcatalog.com/tencent-released-open-source-hy4-preview-model/:

> Tencent has released Hy4 preview, a 770-billion-parameter flagship model with 49 billion active parameters and a one-million-token context window.

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Record: https://forck.live/items/8902-tencent-released-open-source-hy4-preview-model
Catalogue: https://forck.live/llms.txt
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