# Everybody Prune Now: Structured Pruning of LLMs with only Forward Passes

arXiv: https://arxiv.org/abs/2402.05406 · HTML: https://mlsanity.com/paper/2402.05406/

## Key facts

- Cited by 43 papers in the map (data through 14 Oct 2026).
- Builds on 44 of its 63 references that are in the map.
- First posted on arXiv 8 Feb 2024.

## Builds on (most cited first, 30 of 44)

- [Very Deep Convolutional Networks for Large-Scale Image Recognition](https://mlsanity.com/paper/1409.1556/) (2014)
- [Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer](https://mlsanity.com/paper/1910.10683/) (2019)
- [LoRA: Low-Rank Adaptation of Large Language Models](https://mlsanity.com/paper/2106.09685/) (2021)
- [Llama 2: Open Foundation and Fine-Tuned Chat Models](https://mlsanity.com/paper/2307.09288/) (2023)
- [Distilling the Knowledge in a Neural Network](https://mlsanity.com/paper/1503.02531/) (2015)
- [Layer Normalization](https://mlsanity.com/paper/1607.06450/) (2016)
- [DistilBERT, a distilled version of BERT: smaller, faster, cheaper and lighter](https://mlsanity.com/paper/1910.01108/) (2019)
- [Mistral 7B](https://mlsanity.com/paper/2310.06825/) (2023)
- [Pointer Sentinel Mixture Models](https://mlsanity.com/paper/1609.07843/) (2016)
- [Wide Residual Networks](https://mlsanity.com/paper/1605.07146/) (2016)
- [Deep Compression: Compressing Deep Neural Networks with Pruning, Trained Quantization and Huffman Coding](https://mlsanity.com/paper/1510.00149/) (2015)
- [The Lottery Ticket Hypothesis: Finding Sparse, Trainable Neural Networks](https://mlsanity.com/paper/1803.03635/) (2018)
- [SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models](https://mlsanity.com/paper/2211.10438/) (2022)
- [TinyBERT: Distilling BERT for Natural Language Understanding](https://mlsanity.com/paper/1909.10351/) (2019)
- [SparseGPT: Massive Language Models Can Be Accurately Pruned in One-Shot](https://mlsanity.com/paper/2301.00774/) (2023)
- [LLM.int8(): 8-bit Matrix Multiplication for Transformers at Scale](https://mlsanity.com/paper/2208.07339/) (2022)
- [Towards a Unified View of Parameter-Efficient Transfer Learning](https://mlsanity.com/paper/2110.04366/) (2021)
- [Are Sixteen Heads Really Better than One?](https://mlsanity.com/paper/1905.10650/) (2019)
- [A Simple and Effective Pruning Approach for Large Language Models](https://mlsanity.com/paper/2306.11695/) (2023)
- [Distilling Step-by-Step! Outperforming Larger Language Models with Less Training Data and Smaller Model Sizes](https://mlsanity.com/paper/2305.02301/) (2023)
- [LLM-Pruner: On the Structural Pruning of Large Language Models](https://mlsanity.com/paper/2305.11627/) (2023)
- [Textbooks Are All You Need II: phi-1.5 technical report](https://mlsanity.com/paper/2309.05463/) (2023)
- [Sheared LLaMA: Accelerating Language Model Pre-training via Structured Pruning](https://mlsanity.com/paper/2310.06694/) (2023)
- [Movement Pruning: Adaptive Sparsity by Fine-Tuning](https://mlsanity.com/paper/2005.07683/) (2020)
- [SliceGPT: Compress Large Language Models by Deleting Rows and Columns](https://mlsanity.com/paper/2401.15024/) (2024)
- [Fine-Tuning Language Models with Just Forward Passes](https://mlsanity.com/paper/2305.17333/) (2023)
- [Accelerating Sparse Deep Neural Networks](https://mlsanity.com/paper/2104.08378/) (2021)
- [Structured Pruning of Large Language Models](https://mlsanity.com/paper/1910.04732/) (2019)
- [Block Pruning For Faster Transformers](https://mlsanity.com/paper/2109.04838/) (2021)
- [Structured Pruning Learns Compact and Accurate Models](https://mlsanity.com/paper/2204.00408/) (2022)

## Built on by (most cited first, 30 of 43)

- [NVILA: Efficient Frontier Visual Language Models](https://mlsanity.com/paper/2412.04468/) (2024)
- [Compact Language Models via Pruning and Knowledge Distillation](https://mlsanity.com/paper/2407.14679/) (2024)
- [STUN: Structured-Then-Unstructured Pruning for Scalable MoE Pruning](https://mlsanity.com/paper/2409.06211/) (2024)
- [Speech Translation with Speech Foundation Models and Large Language Models: What is There and What is Missing?](https://mlsanity.com/paper/2402.12025/) (2024)
- [Your Transformer is Secretly Linear](https://mlsanity.com/paper/2405.12250/) (2024)
- [Prompt-prompted Adaptive Structured Pruning for Efficient LLM Generation](https://mlsanity.com/paper/2404.01365/) (2024)
- [Instruction-Following Pruning for Large Language Models](https://mlsanity.com/paper/2501.02086/) (2025)
- [ESPACE: Dimensionality Reduction of Activations for Model Compression](https://mlsanity.com/paper/2410.05437/) (2024)
- [A Token is Worth over 1,000 Tokens: Efficient Knowledge Distillation through Low-Rank Clone](https://mlsanity.com/paper/2505.12781/) (2025)
- [Toward Adaptive Large Language Models Structured Pruning via Hybrid-grained Weight Importance Assessment](https://mlsanity.com/paper/2403.10799/) (2024)
- [2SSP: A Two-Stage Framework for Structured Pruning of LLMs](https://mlsanity.com/paper/2501.17771/) (2025)
- [CFSP: An Efficient Structured Pruning Framework for LLMs with Coarse-to-Fine Activation Information](https://mlsanity.com/paper/2409.13199/) (2024)
- [On Fairness of Low-Rank Adaptation of Large Models](https://mlsanity.com/paper/2405.17512/) (2024)
- [Zero Sum SVD: Balancing Loss Sensitivity for Low Rank LLM Compression](https://mlsanity.com/paper/2602.02848/) (2026)
- [ShortOPD: Recovering Pruned LLMs with Short-to-Long On-Policy Distillation](https://mlsanity.com/paper/2607.13124/) (2026)
- [AA-SVD : Anchored and Adaptive SVD for Large Language Model Compression](https://mlsanity.com/paper/2604.02119/) (2026)
- [Bypass Back-propagation: Optimization-based Structural Pruning for Large Language Models via Policy Gradient](https://mlsanity.com/paper/2406.10576/) (2024)
- [Adapt-Pruner: Adaptive Structural Pruning for Efficient Small Language Model Training](https://mlsanity.com/paper/2502.03460/) (2025)
- [On Accelerating Edge AI: Optimizing Resource-Constrained Environments](https://mlsanity.com/paper/2501.15014/) (2025)
- [Towards Alignment-Centric Paradigm: A Survey of Instruction Tuning in Large Language Models](https://mlsanity.com/paper/2508.17184/) (2025)
- [Rethinking Pruning for Vision-Language Models: Strategies for Effective Sparsity and Performance Restoration](https://mlsanity.com/paper/2404.02424/) (2024)
- [VTrans: Accelerating Transformer Compression with Variational Information Bottleneck based Pruning](https://mlsanity.com/paper/2406.05276/) (2024)
- [Structural Pruning of Large Vision Language Models: A Comprehensive Study on Pruning Dynamics, Recovery, and Data Efficiency](https://mlsanity.com/paper/2604.24380/) (2026)
- [Leveraging language models for summarizing mental state examinations: A comprehensive evaluation and dataset release](https://mlsanity.com/paper/2403.20145/) (2024)
- [Zeroth-Order Adaptive Neuron Alignment Based Pruning without Re-Training](https://mlsanity.com/paper/2411.07066/) (2024)
- [SEAP: Training-free Sparse Expert Activation Pruning Unlock the Brainpower of Large Language Models](https://mlsanity.com/paper/2503.07605/) (2025)
- [Meta Pruning via Graph Metanetworks : A Universal Meta Learning Framework for Network Pruning](https://mlsanity.com/paper/2506.12041/) (2025)
- [OverFill: Two-Stage Models for Efficient Language Model Decoding](https://mlsanity.com/paper/2508.08446/) (2025)
- [ROCKET: Rapid Optimization via Calibration-guided Knapsack Enhanced Truncation for Efficient Model Compression](https://mlsanity.com/paper/2602.11008/) (2026)
- [CoCurve: Cross-Module Co-Pruning Curvature for Structured LLM Pruning](https://mlsanity.com/paper/2607.17568/) (2026)

## Abstract (arXiv)

Structured pruning is a promising approach to create smaller, faster large language models. However, existing methods typically rely on computing the gradient via backward passes, which can inflate memory requirements and compute costs. In this work we introduce Bonsai, a gradient-free structured pruning method that eliminates the need for backpropagation, significantly reducing memory requirements and compute costs while achieving state-of-the-art pruning performance. Bonsai uses forward-pass-only perturbative pruning to enable efficient compression of large models on a broader range of hardware configurations. Unlike existing structured pruning approaches, Bonsai not only achieves better compression with fewer resources but also produces models that are twice as fast as those generated by semi-structured pruning. As a concrete demonstration, we use Bonsai to prune 7B and 8B models to 50% sparsity on a single A6000 GPU -- a task challenging for backprop-based methods in memory-constrained settings, as they require 2-3x the memory. Our results show that removing backprop as a requirement not only enables pruning larger models on constrained hardware but can also lead to state-of-the-art efficiency and performance.
