DistilVDR: A Compact End-to-End Visual Document Retriever via Dual-Student Distillation

Zhuchenyang Liu, Ziyi Wang, Yao Zhang, Yu Xiao


Abstract
Visual document retrieval (VDR) is dominated by multi-billion-parameter models that are slow to index at full corpus scale and expensive to serve. Prior compression routes either train a smaller multi-vector encoder from scratch or distil only the query side; neither yields a compact single-vector retriever end-to-end. We present DistilVDR, a 527M end-to-end VDR system distilled bilaterally from a single 8B vision-language teacher under a pointwise cosine alignment loss. All supervision comes from the frozen teacher’s embedding space, which was itself trained with relevance supervision, so the student objective needs no relevance labels, negative sampling, or contrastive term. We match VDR’s text-query and image-document input asymmetry with an asymmetric encoder-only student that concentrates visual capacity on the document side and keeps the query side at 70M parameters. We release two variants that share the same encoders and training and differ only in the document encoder’s visual-tile budget: DistilVDR-HiRes attains 61.74 average NDCG@5 on ViDoRe v1+v2+v3 (86.9% of the 8B teacher) and leads every reproduced sub-1B baseline on the high-resolution-sensitive v3 benchmark, while DistilVDR-Fast attains 59.98 at a 3× smaller visual-token budget. Both variants store one million documents in a 15.6 timessmaller index than the strongest sub-1B multi-vector baseline,and DistilVDR-Fast indexes 5.2 times faster than that baseline and 18 times faster than the teacher.
Anthology ID:
2026.docinsights-1.26
Volume:
The Proceedings of Workshop on Document Intelligence and Understanding
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Santosh T.Y.S.S., Amit Agarwal, Vivek Gupta, Yova Kementchedjhieva, Aparna Garimella, Yufang Hou
Venues:
DocInsights | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
385–399
Language:
URL:
https://aclanthology.org/2026.docinsights-1.26/
DOI:
Bibkey:
Cite (ACL):
Zhuchenyang Liu, Ziyi Wang, Yao Zhang, and Yu Xiao. 2026. DistilVDR: A Compact End-to-End Visual Document Retriever via Dual-Student Distillation. In The Proceedings of Workshop on Document Intelligence and Understanding, pages 385–399, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
DistilVDR: A Compact End-to-End Visual Document Retriever via Dual-Student Distillation (Liu et al., DocInsights 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.docinsights-1.26.pdf