mOSCAR: A Large-scale Multilingual and Multimodal Document-level Corpus

Matthieu Futeral, Armel Randy Zebaze, Pedro Ortiz Suarez, Julien Abadji, Rémi Lacroix, Cordelia Schmid, Rachel Bawden, Benoît Sagot


Abstract
Multimodal Large Language Models (mLLMs) are trained on a large amount of text-image data. While most mLLMs are trained on caption-like data only, Alayrac et al. (2022) showed that additionally training them on interleaved sequences of text and images can lead to the emergence of in-context learning capabilities. However, the dataset they used, M3W, is not public and is only in English. There have been attempts to reproduce their results but the released datasets are English-only. In contrast, current multilingual and multimodal datasets are either composed of caption-like only or medium-scale or fully private data. This limits mLLM research for the 7,000 other languages spoken in the world. We therefore introduce mOSCAR, to the best of our knowledge the first large-scale multilingual and multimodal document corpus crawled from the web. It covers 163 languages, 303M documents, 200B tokens and 1.15B images. We carefully conduct a set of filtering and evaluation steps to make sure mOSCAR is sufficiently safe, diverse and of good quality. We additionally train two types of multilingual model to prove the benefits of mOSCAR: (1) a model trained on a subset of mOSCAR and captioning data and (2) a model trained on captioning data only. The model additionally trained on mOSCAR shows a strong boost in few-shot learning performance across various multilingual image-text tasks and benchmarks, confirming previous findings for English-only mLLMs. The dataset will be made publicly accessible under the Creative Commons CC BY 4.0 license.
Anthology ID:
2025.findings-acl.180
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venues:
Findings | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3461–3494
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URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.180/
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Bibkey:
Cite (ACL):
Matthieu Futeral, Armel Randy Zebaze, Pedro Ortiz Suarez, Julien Abadji, Rémi Lacroix, Cordelia Schmid, Rachel Bawden, and Benoît Sagot. 2025. mOSCAR: A Large-scale Multilingual and Multimodal Document-level Corpus. In Findings of the Association for Computational Linguistics: ACL 2025, pages 3461–3494, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
mOSCAR: A Large-scale Multilingual and Multimodal Document-level Corpus (Futeral et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.180.pdf