From Parameters to Behaviors: A Survey of Model Fusion for Large Language Models
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Abstract (arXiv)
Model fusion integrates the capabilities from source models into a single target model. As of June 2026, Hugging Face hosts more than 2M models. This growing pool provides a rich base for model reuse and capability integration. Yet existing surveys often cover only separate parts of this space, and they do not provide a unified definition or a systematic taxonomy. This survey defines model fusion and organizes prior work into three levels: parameter-level, representation-level, and behavior-level fusion. We also review related metrics, benchmarks, and applications, summarize current challenges, and identify future directions. Our goal is to provide a clear map of this area and support future work on model fusion. A comprehensive list of papers about model fusion is available at https://github.com/Baicaihaochi/Awesome-Model-Fusion-Survey.
Key facts. Cited by 1 paper in the map (data through 14 Oct 2026). Builds on 105 of its 130 references that are in the map. First posted on arXiv 17 Sep 2026.
Builds on
105 of 130 references.
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38 more
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- 2026SMAT: Simple and Efficient Merge-Aware Trainingcited by 0
- 2026SMAT: Simple and Efficient Merge-Aware Training27 Sep 2026