Training-Free Looped Transformers
On the map: Mixture-of-experts → Expert routing strategies
Abstract (arXiv)
We introduce training-free looped transformers, in which a lightweight inference-time wrapper loops a contiguous mid-stack block of layers of a frozen checkpoint without additional fine-tuning, continued training, or architectural changes. Unlike prior looped transformer methods that train with the looped structure end-to-end, we retrofit recurrence onto pretrained models at test time. We show that naive block reapplication usually degrades performance, highlighting the importance of the loop application strategy. Motivated by viewing a pre-norm transformer block as a forward Euler step on an ODE, we instead treat looping as a refinement of the same approximation, replacing one large update with smaller damped sub-steps. Across seven dense, sparse MoE, and MLA+MoE model families, our method improves Qwen3-4B-Instruct by +2.64 pp on MMLU-Pro, Qwen3-30B-A3B-Instruct by +1.14 pp on CommonsenseQA, and Moonlight-16B-A3B-Instruct by +1.20 pp on OpenBookQA.
Key facts. Cited by 12 papers in the map (data through 7 Oct 2026). Placed in Expert routing strategies, one of 12 directions in Mixture-of-experts. Builds on 88 of its 102 references that are in the map. First posted on arXiv 22 May 2026.
Builds on
88 of 102 references.
Closest ancestors · 2
Same direction, newest first
- 2026φ-Balancing for Mixture-of-Experts Training14 May
- 2024MoEUT: Mixture-of-Experts Universal Transformers25 May
Other references · 86
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- 2019ALBERT: A Lite BERT for Self-supervised Learning of Language Representationscited by 2,772
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- 2024MMLU-Pro: A More Robust and Challenging Multi-Task Language Understanding Benchmarkcited by 1,758
- 2024DeepSeek-V2: A Strong, Economical, and Efficient Mixture-of-Experts Language Modelcited by 1,093
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- 2022Transformers learn in-context by gradient descentcited by 714
- 2023C-Eval: A Multi-Level Multi-Discipline Chinese Evaluation Suite for Foundation Modelscited by 694
- 2018Universal Transformerscited by 613
- 2019Deep Equilibrium Modelscited by 603
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- 2022MedMCQA : A Large-scale Multi-Subject Multi-Choice Dataset for Medical domain Question Answeringcited by 525
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- 2025Reasoning with Latent Thoughts: On the Power of Looped Transformerscited by 223
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50 most cited of 86 All 86 (JSON)
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Citing papers per year: 2026: 12.
12 papers.
- 2026On the Residual Scaling of Looped Transformers: Stability and Transferabilitycited by 7
- 2026Loop the Loopies!cited by 4
- 2026AGI Maze as a Benchmark Framework for World-Modeling Agentscited by 2
- 2026Architectural Sampling: Test-Time Scaling via Computational Diversity in Frozen Vision-Language Modelscited by 1
- 2026Penelope: Localized Latent Recurrence for Efficient Structured Reasoningcited by 0
- 2026Write Back the Delta: Revisiting the Same Tokens with Fresh Representationscited by 0
- 2026Improving Test-Time Scaling with Adaptive Looped Transformerscited by 0
- 2026Scheduling Recursive Reasoning in Looped Transformerscited by 0
- 2026Looped Transformers as Optimizerscited by 0
- 2026Decoding Looped Transformers Better for (Almost) Freecited by 0
- 2026Enabling Dynamic Computation in Looped LMscited by 0
- 2026Input-Blind Controls Produce Substantial Oracle Headroom for Layer Programs in Multiple-Choice Evaluationcited by 0
- 2026Input-Blind Controls Produce Substantial Oracle Headroom for Layer Programs in Multiple-Choice Evaluation7 Oct 2026
- 2026Enabling Dynamic Computation in Looped LMs6 Oct 2026
- 2026Decoding Looped Transformers Better for (Almost) Free1 Oct 2026
- 2026Architectural Sampling: Test-Time Scaling via Computational Diversity in Frozen Vision-Language Models1 Oct 2026
- 2026Looped Transformers as Optimizers29 Sep 2026
- 2026Scheduling Recursive Reasoning in Looped Transformers29 Sep 2026
- 2026Improving Test-Time Scaling with Adaptive Looped Transformers28 Sep 2026
- 2026Write Back the Delta: Revisiting the Same Tokens with Fresh Representations26 Sep 2026
- 2026Penelope: Localized Latent Recurrence for Efficient Structured Reasoning28 Jul 2026
- 2026Loop the Loopies!17 Jul 2026
- 2026AGI Maze as a Benchmark Framework for World-Modeling Agents1 Jul 2026
- 2026On the Residual Scaling of Looped Transformers: Stability and Transferability16 Jun 2026
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- 2026FlashLoop: Fast and Memory-Efficient Looped Transformers via Lazy Updates
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- 2026Simply Stabilizing the Loop via Fully Looped Transformer
- 2026Beyond the Training Horizon: Mechanisms and Limits of Length Generalization in Looped Transformers
- 2026One Step Forward and K Steps Back: Better Reasoning with Denoising Recursion Models
- 2026LoopMTP: A looped transformer guided by latent multi-token prediction
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