Tencent introduces SRPO, a research-focused image generation model utilizing Semantic Relative Preference Optimization to align diffusion trajectories with human preference.

On September 1, 2025, Tencent expanded its sophisticated generative AI portfolio with the release of SRPO (Semantic Relative Preference Optimization). This new research model, available as open weights on Hugging Face, represents a significant step forward in how diffusion models are aligned with complex human aesthetic and semantic preferences.
While Tencent's HunyuanImage line continues to drive its enterprise-grade visual generation, SRPO serves as a specialized research vehicle. It aims to solve a fundamental problem in generative modeling: the gap between simple text-to-image alignment and the nuanced, fine-grained preferences that humans use to judge visual quality and compositional accuracy.
The technical core of SRPO lies in its departure from standard reward modeling. Instead of treating image generation as a single-step optimization, SRPO focuses on 'Directly Aligning the Full Diffusion Trajectory.' This means the model optimizes the entire denoising process rather than just the final output.
By implementing Semantic Relative Preference Optimization, the model uses text-conditioned signals to formulate rewards. This allows the model to understand not just 'what' an object is, but 'how' it should be positioned and styled relative to the semantic nuances provided in the prompt. As a fine-tune of the FLUX.1 [dev] architecture, it leverages a high-parameter foundation to achieve superior structural integrity.
SRPO has demonstrated exceptional capabilities in aligning visual outputs with complex linguistic instructions. In comparative testing, the model achieved an Artificial Analysis Elo score of 831, placing it among the top-tier research models for prompt adherence and aesthetic quality.
The model's evaluation methodology focuses on fine-grained human preference. Unlike traditional benchmarks that might only measure CLIP scores, SRPO is evaluated on its ability to navigate the 'diffusion trajectory'—ensuring that every step of the denoising process moves closer to the semantic intent of the user. This results in fewer compositional errors and higher fidelity to long-form descriptive prompts.
For developers looking to integrate SRPO-based capabilities into their workflows, pricing is structured around volume. While the open-weights version allows for local deployment, managed API access provides a scalable alternative for high-throughput applications.
Note that current license terms for the SRPO weights are designated for academic use only. Commercial production use is restricted under the current weight license, though enterprise-grade alternatives within the Hunyuan ecosystem are available for production environments.
SRPO is particularly well-suited for research environments and creative workflows that require high levels of prompt adherence. Because it optimizes the full trajectory, it excels in scenarios where the relationship between multiple objects in a scene is critical.
Ideal applications include high-fidelity concept art generation, academic studies on diffusion alignment, and as a foundation for developing even more specialized fine-tunes. Developers can use the quantized versions to experiment with lower VRAM requirements while maintaining high semantic accuracy.
Developers can access the SRPO model weights directly through Hugging Face. For those working with limited hardware, quantized versions (such as the 8-bit versions developed by the community) are available to facilitate easier local testing.
To dive deeper into the technical implementation, the official GitHub repository provides the source code and research documentation, detailing the mathematical framework behind the Semantic Relative Preference Optimization.
API Pricing — Output: $26 per 1k images