Large Language Models

LLaDA2.1: Speeding Up Text Diffusion via Token Editing

TTiwei BieMMaosong CaoXXiang CaoBBingsen ChenFFuyuan ChenKKun ChenLLun DuDDaozhuo FengHHaibo FengMMingliang GongZZhuocheng GongYYanmei GuJJian GuanKKaiyuan GuanHHongliang HeZZenan HuangJJuyong JiangZZhonghui JiangZZhenzhong LanCChengxi LiJJianguo LiZZehuan LiHHuabin LiuLLin LiuGGuoshan LuYYuan LuYYuxin MaXXingyu MouZZhenxuan PanKKaida QiuYYuji RenJJianfeng TanYYiding TianZZian WangLLanning WeiTTao WuYYipeng XingWWentao YeLLiangyu ZhaTTianze ZhangXXiaolu ZhangJJunbo ZhaoDDa ZhengHHao ZhongWWanli ZhongJJun ZhouJJunlin ZhouLLiwang ZhuMMuzhi ZhuYYihong Zhuang
Published
February 9, 2026
Authors
50

Abstract

While LLaDA2.0 showcased the scaling potential of 100B-level block-diffusion models and their inherent parallelization, the delicate equilibrium between decoding speed and generation quality has remained an elusive frontier. Today, we unveil LLaDA2.1, a paradigm shift designed to transcend this trade-off. By seamlessly weaving Token-to-Token (T2T) editing into the conventional Mask-to-Token (M2T) scheme, we introduce a joint, configurable threshold-decoding scheme. This structural innovation gives rise to two distinct personas: the Speedy Mode (S Mode), which audaciously lowers the M2T threshold to bypass traditional constraints while relying on T2T to refine the output; and the Quality Mode (Q Mode), which leans into conservative thresholds to secure superior benchmark performances with manageable efficiency degrade. Furthering this evolution, underpinned by an expansive context window, we implement the first large-scale Reinforcement Learning (RL) framework specifically tailored for dLLMs, anchored by specialized techniques for stable gradient estimation. This alignment not only sharpens reasoning precision but also elevates instruction-following fidelity, bridging the chasm between diffusion dynamics and complex human intent. We culminate this work by releasing LLaDA2.1-Mini (16B) and LLaDA2.1-Flash (100B). Across 33 rigorous benchmarks, LLaDA2.1 delivers strong task performance and lightning-fast decoding speed. Despite its 100B volume, on coding tasks it attains an astounding 892 TPS on HumanEval+, 801 TPS on BigCodeBench, and 663 TPS on LiveCodeBench.

Keywords

block-diffusion modelsdecoding speedgeneration qualityToken-to-Token editingMask-to-Token schemethreshold-decoding schemeSpeedy ModeQuality ModeReinforcement Learninggradient estimationreasoning precisioninstruction-followinglarge language diffusion modelsHumanEval+BigCodeBenchLiveCodeBench

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