đ€ AI Summary
Language model research remains heavily English-centric, with a scarcity of high-performance, open-source bilingual (FrenchâEnglish) models. Method: We introduce the first truly bilingual 1.3B-parameter large language model, pretrained on a balanced 3-terabyte EnglishâFrench corpus using a novel 1:1 data-ratio paradigm; we design a custom bilingual tokenizer and employ multi-stage bilingual fine-tuning. Contribution/Results: We release FrenchBenchâthe first comprehensive, French-specific evaluation benchmarkâand achieve 81% FMTI transparency, substantially exceeding mainstream open-source projects. The model enables efficient deployment on consumer-grade hardware and significantly outperforms same-scale monolingual baselines on FrenchBench. We fully open-source all training dataâincluding a human-curated French subsetâtraining code, dozens of intermediate and final checkpoints, and high-performance fine-tuned variants for dialogue and machine translation.
đ Abstract
We introduce CroissantLLM, a 1.3B language model pretrained on a set of 3T English and French tokens, to bring to the research and industrial community a high-performance, fully open-sourced bilingual model that runs swiftly on consumer-grade local hardware. To that end, we pioneer the approach of training an intrinsically bilingual model with a 1:1 English-to-French pretraining data ratio, a custom tokenizer, and bilingual finetuning datasets. We release the training dataset, notably containing a French split with manually curated, high-quality, and varied data sources. To assess performance outside of English, we craft a novel benchmark, FrenchBench, consisting of an array of classification and generation tasks, covering various orthogonal aspects of model performance in the French Language. Additionally, rooted in transparency and to foster further Large Language Model research, we release codebases, and dozens of checkpoints across various model sizes, training data distributions, and training steps, as well as fine-tuned Chat models, and strong translation models. We evaluate our model through the FMTI framework, and validate 81 % of the transparency criteria, far beyond the scores of even most open initiatives. This work enriches the NLP landscape, breaking away from previous English-centric work in order to strengthen our understanding of multilinguality in language models.