LadderEdit: Edit-Level Residual Compression for Memory-Efficient Lifelong Editing of LLMs

Xiaobing Yu, Peijie Qiu, Jin Yang, Xuanzhao Dong, Weiwei Ma, Zhaoqi An, Xiaoqi Zhao, Xiaofeng Liu


Abstract
Lifelong editing of LLMs requires storing thousands of edits after acquisition. A widely used family of approaches attaches one LoRA adapter per edit, which preserves behavior but grows linearly in storage. To address this challenge, we propose LadderEdit, a method that compresses each LoRA adapter after it is acquired. Each edit is first stored at low rank as a cheap sketch. We then check whether this sketch still satisfies the rewrite, generalization, and locality contract on probe prompts. Edits that pass keep the sketch; those that fail are promoted to a higher rank along a ladder until the contract is met. Because every edit retains some representation, coverage is maintained, and only hard edits consume more rank. Across ZsRE, CounterFact, and WikiBigEdit benchmarks on LLaMA-3-8B, Mistral-7B, and Qwen2.5-7B, LadderEdit tracks exact LoRA storage at 5.2× less memory and remains effective at 50,000 sequential edits.
Anthology ID:
2026.emnlp-main.1261
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:
28738–28764
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1261/
DOI:
Bibkey:
Cite (ACL):
Xiaobing Yu, Peijie Qiu, Jin Yang, Xuanzhao Dong, Weiwei Ma, Zhaoqi An, Xiaoqi Zhao, and Xiaofeng Liu. 2026. LadderEdit: Edit-Level Residual Compression for Memory-Efficient Lifelong Editing of LLMs. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 28738–28764, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LadderEdit: Edit-Level Residual Compression for Memory-Efficient Lifelong Editing of LLMs (Yu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1261.pdf