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Niklas Muennighoff

40 accepted papers

2026

ATLAS: Adaptive Transfer Scaling Laws for Multilingual Pretraining, Finetuning, and Decoding the Curse of Multilinguality

ICLR 2026poster

Scaling laws research has focused overwhelmingly on English—yet the most prominent AI models explicitly serve billions of international users. In this work, we undertake the largest multilingual scaling laws study to date, totaling 774 multilingual training experiments, spanning 10M-8B model paramet…

Cited by 0SourceScholar
2026

HUME: Measuring the Human-Model Performance Gap in Text Embedding Tasks

ICLR 2026poster

Comparing human and model performance offers a valuable perspective for understanding the strengths and limitations of embedding models, highlighting wherethey succeed and where they fail to capture meaning and nuance. However, such comparisons are rarely made, as human performance on embedding task…

Cited by 0SourcecodeScholar
2026

OpenThoughts: Data Recipes for Reasoning Models

ICLR 2026oral

Reasoning models have made rapid progress on many benchmarks involving math, code, and science. Yet, there are still many open questions about the best train- ing recipes for reasoning since state-of-the-art models often rely on proprietary datasets with little to no public information available. To…

Cited by 0SourcecodeScholar
2026

Terminal-Bench: Benchmarking Agents on Hard, Realistic Tasks in Command Line Interfaces

ICLR 2026poster

AI agents may soon become capable of autonomously completing valuable, long-horizon tasks in diverse domains. Current benchmarks either do not measure real-world tasks, or are not sufficiently difficult to meaningfully measure frontier models. To this end, we present Terminal-Bench 1.5: a carefully…

Cited by 0SourcecodeScholar
2026

When Visualizing is the First Step to Reasoning: MIRA, a Benchmark for Visual Chain-of-Thought

CVPR 2026

We propose MIRA (Multimodal Imagination for Reasoning Assessment), a new benchmark designed to evaluate models in scenarios where generating intermediate visual images is essential for successful reasoning. Unlike traditional Chain-of-thought (CoT) methods that rely solely on text, tasks in MIRA req

Cited by 0SourcecodeScholar
2025

Aurora-M: Open Source Continual Pre-training for Multilingual Language and Code

COLING 2025industry

Pretrained language models are integral part of AI applications, but their high computational cost for training limits accessibility. Initiatives such as Bloom and StarCoder aim to democratize access to pretrained models for collaborative community development. Despite these efforts, such models enc…

Cited by 2SourcePDFScholar
2025

BRIGHT: A Realistic and Challenging Benchmark for Reasoning-Intensive Retrieval

ICLR 2025spotlight

Existing retrieval benchmarks primarily consist of information-seeking queries (e.g., aggregated questions from search engines) where keyword or semantic-based retrieval is usually sufficient. However, many complex real-world queries require in-depth reasoning to identify relevant documents that go…

Cited by 24SourcePDFScholar
2025

BigCodeBench: Benchmarking Code Generation with Diverse Function Calls and Complex Instructions

ICLR 2025oral

Task automation has been greatly empowered by the recent advances in Large Language Models (LLMs) via Python code, where the tasks range from software engineering development to general-purpose reasoning. While current benchmarks have shown that LLMs can solve tasks using programs like human develop…

Cited by 609SourcePDFScholar
2025

Bridging the Data Provenance Gap Across Text, Speech, and Video

ICLR 2025poster

Progress in AI is driven largely by the scale and quality of training data. Despite this, there is a deficit of empirical analysis examining the attributes of well-established datasets beyond text. In this work we conduct the largest and first-of-its-kind longitudinal audit across modalities --- pop…

Cited by 1SourcePDFScholar
2025

FlexOLMo: Open Language Models for Flexible Data Use

NeurIPS 2025spotlight

We introduce FlexOLMo, a new class of language models (LMs) that supports (1) distributed training without data sharing, where different model parameters are independently trained on private datasets, and (2) data-flexible inference, where these parameters along with their associated data can be eas…

Cited by 0SourceScholar
2025

Generative Representational Instruction Tuning

ICLR 2025poster

All text-based language problems can be reduced to either generation or embedding. Current models only perform well at one or the other. We introduce generative representational instruction tuning (GRIT) whereby a large language model is trained to handle both generative and embedding tasks by disti…

2025

KMMLU: Measuring Massive Multitask Language Understanding in Korean

NAACL 2025long

We propose KMMLU, a Korean benchmark with 35,030 expert-level multiple-choice questions across 45 subjects ranging from humanities to STEM. While prior Korean evaluation tools heavily rely on translated versions of existing English benchmarks, KMMLU is collected from original Korean exams, thereby c…

2025

LLM-as-an-Interviewer: Beyond Static Testing Through Dynamic LLM Evaluation

ACL 2025finding

We introduce LLM-as-an-Interviewer, a novel paradigm for evaluating large language models (LLMs). This approach leverages multi-turn interactions where the LLM interviewer actively provides feedback on responses and poses follow-up questions to the evaluated LLM. At the start of the interview, the L…

2025

Language models scale reliably with over-training and on downstream tasks

ICLR 2025poster

Scaling laws are useful guides for derisking expensive training runs, as they predict performance of large models using cheaper, small-scale experiments. However, there remain gaps between current scaling studies and how language models are ultimately trained and evaluated. For instance, scaling is…

2025

MIEB: Massive Image Embedding Benchmark

ICCV 2025poster

Image representations are often evaluated through disjointed, task-specific protocols, leading to a fragmented understanding of model capabilities. For instance, it is unclear whether an image embedding model adept at clustering images is equally good at retrieving relevant images given a piece of t…

2025

MMTEB: Massive Multilingual Text Embedding Benchmark

ICLR 2025poster

Text embeddings are typically evaluated on a narrow set of tasks, limited in terms of languages, domains, and task types. To circumvent this limitation and to provide a more comprehensive evaluation, we introduce the Massive Multilingual Text Embedding Benchmark (MMTEB) -- a large-scale community-dr…

2025

Molmo and PixMo: Open Weights and Open Data for State-of-the-Art Vision-Language Models

CVPR 2025award

Today's most advanced vision-language models (VLMs) remain proprietary. The strongest open-weight models rely heavily on synthetic data from proprietary VLMs to achieve good performance, effectively distilling these closed VLMs into open ones. As a result, the community has been missing foundational…

2025

OLMoE: Open Mixture-of-Experts Language Models

ICLR 2025oral

We introduce OLMoE, a fully open, state-of-the-art language model leveraging sparse Mixture-of-Experts (MoE). OLMoE-1B-7B has 7 billion (B) parameters but uses only 1B per input token. We pretrain it on 5 trillion tokens and further adapt it to create OLMoE-1B-7B-Instruct. Our models outperform all…

2025

OpenHands: An Open Platform for AI Software Developers as Generalist Agents

ICLR 2025poster

Software is one of the most powerful tools that we humans have at our disposal; it allows a skilled programmer to interact with the world in complex and profound ways. At the same time, thanks to improvements in large language models (LLMs), there has also been a rapid development in AI agents that…

Cited by 32SourcePDFScholar
2025

RegMix: Data Mixture as Regression for Language Model Pre-training

ICLR 2025spotlight

The data mixture for large language model pre-training significantly impacts performance, yet how to determine an effective mixture remains unclear. We propose RegMix to automatically identify a high-performing data mixture by formulating it as a regression task. RegMix trains many small models on d…

2025

SWE-bench Multimodal: Do AI Systems Generalize to Visual Software Domains?

ICLR 2025poster

Autonomous systems for software engineering are now capable of fixing bugs and developing features. These systems are commonly evaluated on SWE-bench (Jimenez et al., 2024a), which assesses their ability to solve software issues from GitHub repositories. However, SWE-bench uses only Python repositor…

Cited by 198SourcePDFScholar
2025

Scaling Laws for Precision

ICLR 2025oral

Low precision training and inference affect both the quality and cost of language models, but current scaling laws do not account for this. In this work, we devise "precision-aware" scaling laws for both training and inference. We propose that training in lower precision reduces the model's "effecti…

Cited by 24SourcePDFScholar
2025

s1: Simple test-time scaling

EMNLP 2025

Test-time scaling is a promising new approach to language modeling that uses extra test-time compute to improve performance. Recently, OpenAI’s o1 model showed this capability but did not publicly share its methodology, leading to many replication efforts. We seek the simplest approach to achieve te

2024

Aya Dataset: An Open-Access Collection for Multilingual Instruction Tuning

ACL 2024long

Datasets are foundational to many breakthroughs in modern artificial intelligence. Many recent achievements in the space of natural language processing (NLP) can be attributed to the fine-tuning of pre-trained models on a diverse set of tasks that enables a large language model (LLM) to respond to i…

Cited by 94SourcePDFScholar
2024

Aya Model: An Instruction Finetuned Open-Access Multilingual Language Model

ACL 2024long

Recent breakthroughs in large language models (LLMs) have centered around a handful of data-rich languages. What does it take to broaden access to breakthroughs beyond first-class citizen languages? Our work introduces Aya, a massively multilingual generative language model that follows instructions…

Cited by 181SourcePDFScholar
2024

Consent in Crisis: The Rapid Decline of the AI Data Commons

NeurIPS 2024poster

General-purpose artificial intelligence (AI) systems are built on massive swathes of public web data, assembled into corpora such as C4, RefinedWeb, and Dolma. To our knowledge, we conduct the first, large-scale, longitudinal audit of the consent protocols for the web domains underlying AI training…

Cited by 36SourceScholar
2024

DataComp-LM: In search of the next generation of training sets for language models

NeurIPS 2024poster

We introduce DataComp for Language Models, a testbed for controlled dataset experiments with the goal of improving language models. As part of DCLM, we provide a standardized corpus of 240T tokens extracted from Common Crawl, effective pretraining recipes based on the OpenLM framework, and a broad s…

Cited by 64SourcePDFScholar
2024

Dolma: an Open Corpus of Three Trillion Tokens for Language Model Pretraining Research

ACL 2024long

Information about pretraining corpora used to train the current best-performing language models is seldom discussed: commercial models rarely detail their data, and even open models are often released without accompanying training data or recipes to reproduce them. As a result, it is challenging to…

2024

Model Alignment as Prospect Theoretic Optimization

ICML 2024spotlight

Kahneman & Tversky's $\textit{prospect theory}$ tells us that humans perceive random variables in a biased but well-defined manner (1992); for example, humans are famously loss-averse. We show that objectives for aligning LLMs with human feedback implicitly incorporate many of these biases---the suc…

Cited by 32SourcePDFScholar
2024

OLMo: Accelerating the Science of Language Models

ACL 2024long

Language models (LMs) have become ubiquitous in both NLP research and in commercial product offerings. As their commercial importance has surged, the most powerful models have become closed off, gated behind proprietary interfaces, with important details of their training data, architectures, and de…

2024

OctoPack: Instruction Tuning Code Large Language Models

ICLR 2024spotlight

Finetuning large language models (LLMs) on instructions leads to vast performance improvements on natural language tasks. We apply instruction tuning using code, leveraging the natural structure of Git commits, which pair code changes with human instructions. We compile CommitPack: 4 terabytes of Gi…

2024

SEACrowd: A Multilingual Multimodal Data Hub and Benchmark Suite for Southeast Asian Languages

EMNLP 2024main

Southeast Asia (SEA) is a region rich in linguistic diversity and cultural variety, with over 1,300 indigenous languages and a population of 671 million people. However, prevailing AI models suffer from a significant lack of representation of texts, images, and audio datasets from SEA, compromising…

2024

Scaling Laws with Vocabulary: Larger Models Deserve Larger Vocabularies

NeurIPS 2024poster

Research on scaling large language models (LLMs) has primarily focused on model parameters and training data size, overlooking the role of vocabulary size. We investigate how vocabulary size impacts LLM scaling laws by training models ranging from 33M to 3B parameters on up to 500B characters with v…

2024

The Scandinavian Embedding Benchmarks: Comprehensive Assessment of Multilingual and Monolingual Text Embedding

NeurIPS 2024poster

The evaluation of English text embeddings has transitioned from evaluating a handful of datasets to broad coverage across many tasks through benchmarks such as MTEB. However, this is not the case for multilingual text embeddings due to a lack of available benchmarks. To address this problem, we intr…

Cited by 16SourcePDFScholar
2023

BLOOM+1: Adding Language Support to BLOOM for Zero-Shot Prompting

ACL 2023long

The BLOOM model is a large publicly available multilingual language model, but its pretraining was limited to 46 languages. To extend the benefits of BLOOM to other languages without incurring prohibitively large costs, it is desirable to adapt BLOOM to new languages not seen during pretraining. In…

2023

Crosslingual Generalization through Multitask Finetuning

ACL 2023long

Multitask prompted finetuning (MTF) has been shown to help large language models generalize to new tasks in a zero-shot setting, but so far explorations of MTF have focused on English data and models. We apply MTF to the pretrained multilingual BLOOM and mT5 model families to produce finetuned varia…

2023

FinGPT: Large Generative Models for a Small Language

EMNLP 2023long main

Large language models (LLMs) excel in many tasks in NLP and beyond, but most open models have very limited coverage of smaller languages and LLM work tends to focus on languages where nearly unlimited data is available for pretraining. In this work, we study the challenges of creating LLMs for Finni…

Cited by 0SourceScholar
2023

Scaling Data-Constrained Language Models

NeurIPS 2023oral

The current trend of scaling language models involves increasing both parameter count and training dataset size. Extrapolating this trend suggests that training dataset size may soon be limited by the amount of text data available on the internet. Motivated by this limit, we investigate scaling lang…

2022

What Language Model to Train if You Have One Million GPU Hours?

EMNLP 2022finding

The crystallization of modeling methods around the Transformer architecture has been a boon for practitioners. Simple, well-motivated architectural variations can transfer across tasks and scale, increasing the impact of modeling research. However, with the emergence of state-of-the-art 100B+ parame…