Jasper-Flash: Elastic Token Compression and Progressive Distillation for Inference-Scalable Text Embedding Models

Haining An, Xingbing Chen, Wenbo Lyu, Dun Zhang, Ziyang Zeng, Zhenxiang Zhao, Rui Song, Hao Xu


Abstract
Deploying text embedding models under resource constraints is challenged by the sequence-length-dependent computational cost of self-attention. However, existing sequence-reduction strategies remain predominantly static and offer limited flexibility across inference budgets. We propose Jasper-Flash, an inference-scalable text embedding framework combining Elastic Token Compression (ETC) with Compression-Adaptive Progressive Distillation (CAPD). ETC uses a length threshold and a user-selected compression ratio to adjust sequence length on the fly, enabling flexible latency–quality trade-offs within a single model. To mitigate the optimization difficulty introduced by lossy sequence reduction, CAPD integrates heterogeneous multi-teacher distillation with a progressive curriculum over fixed and dynamically sampled compression ratios. We instantiate Jasper-Flash as Jasper-Token-Compression-600M, a bilingual text embedding model. Experiments on MTEB and C-MTEB demonstrate competitive performance across compression ratios and substantial reductions in encoding latency, particularly for longer inputs. The code and model are available at https://huggingface.co/infgrad/Jasper-Token-Compression-600M.
Anthology ID:
2026.emnlp-main.1125
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
25766–25789
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URL:
https://aclanthology.org/2026.emnlp-main.1125/
DOI:
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Cite (ACL):
Haining An, Xingbing Chen, Wenbo Lyu, Dun Zhang, Ziyang Zeng, Zhenxiang Zhao, Rui Song, and Hao Xu. 2026. Jasper-Flash: Elastic Token Compression and Progressive Distillation for Inference-Scalable Text Embedding Models. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 25766–25789, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Jasper-Flash: Elastic Token Compression and Progressive Distillation for Inference-Scalable Text Embedding Models (An et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.1125.pdf