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author Amini, Alexander
Banaszak, Anna
Benoit, Harold
Böök, Arthur
Dakhran, Tarek
Duong, Song
Eng, Alfred
Fernandes, Fernando
Härkönen, Marc
Harrington, Anne
Hasani, Ramin
Karwa, Saniya
Khrustalev, Yuri
Labonne, Maxime
Lechner, Mathias
Lechner, Valentine
Lee, Simon
Li, Zetian
Loo, Noel
Marks, Jacob
Mosca, Edoardo
Paech, Samuel J.
Pak, Paul
Parnichkun, Rom N.
Quach, Alex
Rogers, Ryan
Rus, Daniela
Saxena, Nayan
Schlager, Bettina
Seyde, Tim
Smith, Jimmy T. H.
Tadimeti, Aditya
Tumma, Neehal
author_facet Amini, Alexander
Banaszak, Anna
Benoit, Harold
Böök, Arthur
Dakhran, Tarek
Duong, Song
Eng, Alfred
Fernandes, Fernando
Härkönen, Marc
Harrington, Anne
Hasani, Ramin
Karwa, Saniya
Khrustalev, Yuri
Labonne, Maxime
Lechner, Mathias
Lechner, Valentine
Lee, Simon
Li, Zetian
Loo, Noel
Marks, Jacob
Mosca, Edoardo
Paech, Samuel J.
Pak, Paul
Parnichkun, Rom N.
Quach, Alex
Rogers, Ryan
Rus, Daniela
Saxena, Nayan
Schlager, Bettina
Seyde, Tim
Smith, Jimmy T. H.
Tadimeti, Aditya
Tumma, Neehal
contents We present LFM2, a family of Liquid Foundation Models designed for efficient on-device deployment and strong task capabilities. Using hardware-in-the-loop architecture search under edge latency and memory constraints, we obtain a compact hybrid backbone that combines gated short convolutions with a small number of grouped query attention blocks, delivering up to 2x faster prefill and decode on CPUs compared to similarly sized models. The LFM2 family covers 350M-8.3B parameters, including dense models (350M, 700M, 1.2B, 2.6B) and a mixture-of-experts variant (8.3B total, 1.5B active), all with 32K context length. LFM2's training pipeline includes a tempered, decoupled Top-K knowledge distillation objective that avoids support mismatch; curriculum learning with difficulty-ordered data; and a three-stage post-training recipe of supervised fine-tuning, length-normalized preference optimization, and model merging. Pre-trained on 10-12T tokens, LFM2 models achieve strong results across diverse benchmarks; for example, LFM2-2.6B reaches 79.56% on IFEval and 82.41% on GSM8K. We further build multimodal and retrieval variants: LFM2-VL for vision-language tasks, LFM2-Audio for speech, and LFM2-ColBERT for retrieval. LFM2-VL supports tunable accuracy-latency tradeoffs via token-efficient visual processing, while LFM2-Audio separates audio input and output pathways to enable real-time speech-to-speech interaction competitive with models 3x larger. LFM2-ColBERT provides a low-latency encoder for queries and documents, enabling high-performance retrieval across multiple languages. All models are released with open weights and deployment packages for ExecuTorch, llama.cpp, and vLLM, making LFM2 a practical base for edge applications that need fast, memory-efficient inference and strong task capabilities.
format Preprint
id arxiv_https___arxiv_org_abs_2511_23404
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle LFM2 Technical Report
Amini, Alexander
Banaszak, Anna
Benoit, Harold
Böök, Arthur
Dakhran, Tarek
Duong, Song
Eng, Alfred
Fernandes, Fernando
Härkönen, Marc
Harrington, Anne
Hasani, Ramin
Karwa, Saniya
Khrustalev, Yuri
Labonne, Maxime
Lechner, Mathias
Lechner, Valentine
Lee, Simon
Li, Zetian
Loo, Noel
Marks, Jacob
Mosca, Edoardo
Paech, Samuel J.
Pak, Paul
Parnichkun, Rom N.
Quach, Alex
Rogers, Ryan
Rus, Daniela
Saxena, Nayan
Schlager, Bettina
Seyde, Tim
Smith, Jimmy T. H.
Tadimeti, Aditya
Tumma, Neehal
Machine Learning
Artificial Intelligence
We present LFM2, a family of Liquid Foundation Models designed for efficient on-device deployment and strong task capabilities. Using hardware-in-the-loop architecture search under edge latency and memory constraints, we obtain a compact hybrid backbone that combines gated short convolutions with a small number of grouped query attention blocks, delivering up to 2x faster prefill and decode on CPUs compared to similarly sized models. The LFM2 family covers 350M-8.3B parameters, including dense models (350M, 700M, 1.2B, 2.6B) and a mixture-of-experts variant (8.3B total, 1.5B active), all with 32K context length. LFM2's training pipeline includes a tempered, decoupled Top-K knowledge distillation objective that avoids support mismatch; curriculum learning with difficulty-ordered data; and a three-stage post-training recipe of supervised fine-tuning, length-normalized preference optimization, and model merging. Pre-trained on 10-12T tokens, LFM2 models achieve strong results across diverse benchmarks; for example, LFM2-2.6B reaches 79.56% on IFEval and 82.41% on GSM8K. We further build multimodal and retrieval variants: LFM2-VL for vision-language tasks, LFM2-Audio for speech, and LFM2-ColBERT for retrieval. LFM2-VL supports tunable accuracy-latency tradeoffs via token-efficient visual processing, while LFM2-Audio separates audio input and output pathways to enable real-time speech-to-speech interaction competitive with models 3x larger. LFM2-ColBERT provides a low-latency encoder for queries and documents, enabling high-performance retrieval across multiple languages. All models are released with open weights and deployment packages for ExecuTorch, llama.cpp, and vLLM, making LFM2 a practical base for edge applications that need fast, memory-efficient inference and strong task capabilities.
title LFM2 Technical Report
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2511.23404