Perception Compressor: A Training-Free Prompt Compression Framework in Long Context Scenarios
Jiwei Tang, Jin Xu, Tingwei Lu, Zhicheng Zhang, YimingZhao YimingZhao, LinHai LinHai, Hai-Tao Zheng
Abstract
Large language models (LLMs) demonstrate exceptional capabilities in various scenarios. However, they suffer from much redundant information and are sensitive to the position of key information in long context scenarios. To address these challenges, we present Perception Compressor, a training-free prompt compression framework. It includes a perception retriever that leverages guiding questions and instruction to retrieve the most relevant demonstrations, a dual-slope ratio allocator to dynamically allocate compression ratios and open-book ratios, and a semi-guided iterative compression that retains key information at the token level while removing tokens that distract the LLM. We conduct extensive experiments on long context benchmarks, i.e., NaturalQuestions, LongBench, and MuSiQue. Experiment results show that Perception Compressor outperforms existing methods by a large margin, achieving state-of-the-art performance.- Anthology ID:
- 2025.findings-naacl.229
- Volume:
- Findings of the Association for Computational Linguistics: NAACL 2025
- Month:
- April
- Year:
- 2025
- Address:
- Albuquerque, New Mexico
- Editors:
- Luis Chiruzzo, Alan Ritter, Lu Wang
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 4093–4108
- Language:
- URL:
- https://preview.aclanthology.org/Ingest-2025-COMPUTEL/2025.findings-naacl.229/
- DOI:
- Cite (ACL):
- Jiwei Tang, Jin Xu, Tingwei Lu, Zhicheng Zhang, YimingZhao YimingZhao, LinHai LinHai, and Hai-Tao Zheng. 2025. Perception Compressor: A Training-Free Prompt Compression Framework in Long Context Scenarios. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 4093–4108, Albuquerque, New Mexico. Association for Computational Linguistics.
- Cite (Informal):
- Perception Compressor: A Training-Free Prompt Compression Framework in Long Context Scenarios (Tang et al., Findings 2025)
- PDF:
- https://preview.aclanthology.org/Ingest-2025-COMPUTEL/2025.findings-naacl.229.pdf