Exploring Design Choices for Building Language-Specific LLMs
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Abstract (arXiv)
Despite rapid progress in large language models (LLMs), their performance on a vast majority of languages remains unsatisfactory. In this paper, we study building language-specific LLMs by adapting monolingual and multilingual LLMs. We conduct systematic experiments on how design choices (base model selection, vocabulary extension, and continued pretraining) impact the adapted LLM, both in terms of efficiency (how many tokens are needed to encode the same amount of information) and end task performance. We find that (1) the initial performance of LLM does not always correlate with the final performance after the adaptation. Adapting an English-centric models can yield better results than adapting multilingual models despite their worse initial performance on low-resource languages. (2) Efficiency can easily improved with simple vocabulary extension and continued pretraining in most LLMs we study, and (3) The optimal adaptation method (choice of the base model, new vocabulary size, training data, initialization strategy) is highly language-dependent, and the simplest embedding initialization works well across various experimental settings. Together, our work lays foundations on efficiently building language-specific LLMs by adapting existing LLMs.
Key facts. Cited by 22 papers in the map (data through 7 Oct 2026). Builds on 30 of its 46 references that are in the map. First posted on arXiv 20 Jun 2024.
Builds on
30 of 46 references.
References · 30
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- 2015Neural Machine Translation of Rare Words with Subword Unitscited by 2,898
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- 2024Aya Model: An Instruction Finetuned Open-Access Multilingual Language Modelcited by 292
- 2023Do All Languages Cost the Same? Tokenization in the Era of Commercial Language Modelscited by 186
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- 2023Efficiently Adapting Pretrained Language Models To New Languagescited by 28
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Built on by
Citing papers per year: 2024: 8; 2025: 8; 2026: 6.
22 papers.
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- 2024MEXA: Multilingual Evaluation of English-Centric LLMs via Cross-Lingual Alignmentcited by 25
- 2024EMMA-500: Enhancing Massively Multilingual Adaptation of Large Language Modelscited by 16
- 2025TituLLMs: A Family of Bangla LLMs with Comprehensive Benchmarkingcited by 9
- 2024Efficient Continual Pre-training of LLMs for Low-resource Languagescited by 8
- 2024Facilitating large language model Russian adaptation with Learned Embedding Propagationcited by 8
- 2024Multilingual Arbitrage: Optimizing Data Pools to Accelerate Multilingual Progresscited by 6
- 2024Adapting Chat Language Models Using Only Target Unlabeled Language Datacited by 6
- 2024From English-Centric to Effective Bilingual: LLMs with Custom Tokenizers for Underrepresented Languagescited by 5
- 2026Stop Taking Tokenizers for Granted: They Are Core Design Decisions in Large Language Modelscited by 5
- 2024Why We Build Local Large Language Models: An Observational Analysis from 35 Japanese and Multilingual LLMscited by 4
- 2025Evaluation of LLMs in Medical Text Summarization: The Role of Vocabulary Adaptation in High OOV Settingscited by 4
- 2025Mitigating Catastrophic Forgetting in Target Language Adaptation of LLMs via Source-Shielded Updatescited by 4
10 more
- 2025Prune or Retrain: Optimizing the Vocabulary of Multilingual Models for Estoniancited by 3
- 2025Teaching Old Tokenizers New Words: Efficient Tokenizer Adaptation for Pre-trained Modelscited by 2
- 2026How Does "English (US)" Become the Default? Triangulating Structural Bias Towards American English Across the LLM Pipelinecited by 2
- 2025Improving Multilingual Capabilities with Cultural and Local Knowledge in Large Language Models While Enhancing Native Performancecited by 1
- 2025Vocabulary Customization for Efficient Domain-Specific LLM Deploymentcited by 1
- 2026MultiHashFormer: Hash-based Generative Language Modelscited by 1
- 2025Prompt, Translate, Fine-Tune, Re-Initialize, or Instruction-Tune? Adapting LLMs for In-Context Learning in Low-Resource Languagescited by 0
- 2026Reading the News: Adapting Large Language Models to Swedish Journalism Through Continued Pre-Trainingcited by 0
- 2026From Zero to Hero: An Open LLM Ecosystem for Armeniancited by 0
- 2026To Each Language Its Tokenizer: Modular Tokenizers for Efficient Multilingual LLMscited by 0
- 2026To Each Language Its Tokenizer: Modular Tokenizers for Efficient Multilingual LLMs14 Sep 2026
- 2026From Zero to Hero: An Open LLM Ecosystem for Armenian3 Sep 2026
- 2026Reading the News: Adapting Large Language Models to Swedish Journalism Through Continued Pre-Training31 Aug 2026
- 2026MultiHashFormer: Hash-based Generative Language Models26 Jun 2026
- 2026How Does "English (US)" Become the Default? Triangulating Structural Bias Towards American English Across the LLM Pipeline5 Apr 2026
- 2026Stop Taking Tokenizers for Granted: They Are Core Design Decisions in Large Language Models19 Jan 2026
- 2025Mitigating Catastrophic Forgetting in Target Language Adaptation of LLMs via Source-Shielded Updates4 Dec 2025
- 2025Teaching Old Tokenizers New Words: Efficient Tokenizer Adaptation for Pre-trained Models3 Dec 2025
- 2025Vocabulary Customization for Efficient Domain-Specific LLM Deployment30 Sep 2025
- 2025Prompt, Translate, Fine-Tune, Re-Initialize, or Instruction-Tune? Adapting LLMs for In-Context Learning in Low-Resource Languages23 Jun 2025
- 2025Evaluation of LLMs in Medical Text Summarization: The Role of Vocabulary Adaptation in High OOV Settings27 May 2025
- 2025Improving Multilingual Capabilities with Cultural and Local Knowledge in Large Language Models While Enhancing Native Performance13 Apr 2025
10 more
- 2025TituLLMs: A Family of Bangla LLMs with Comprehensive Benchmarking16 Feb 2025
- 2025Prune or Retrain: Optimizing the Vocabulary of Multilingual Models for Estonian5 Jan 2025
- 2024Facilitating large language model Russian adaptation with Learned Embedding Propagation30 Dec 2024
- 2024Why We Build Local Large Language Models: An Observational Analysis from 35 Japanese and Multilingual LLMs19 Dec 2024
- 2024Adapting Chat Language Models Using Only Target Unlabeled Language Data16 Dec 2024
- 2024Efficient Continual Pre-training of LLMs for Low-resource Languages13 Dec 2024
- 2024From English-Centric to Effective Bilingual: LLMs with Custom Tokenizers for Underrepresented Languages24 Oct 2024
- 2024MEXA: Multilingual Evaluation of English-Centric LLMs via Cross-Lingual Alignment8 Oct 2024
- 2024EMMA-500: Enhancing Massively Multilingual Adaptation of Large Language Models26 Sep 2024
- 2024Multilingual Arbitrage: Optimizing Data Pools to Accelerate Multilingual Progress27 Aug 2024
- 2024MEXA: Multilingual Evaluation of English-Centric LLMs via Cross-Lingual Alignmentcited by 25
- 2024EMMA-500: Enhancing Massively Multilingual Adaptation of Large Language Modelscited by 16
- 2025TituLLMs: A Family of Bangla LLMs with Comprehensive Benchmarkingcited by 9
- 2024Efficient Continual Pre-training of LLMs for Low-resource Languagescited by 8
- 2024Facilitating large language model Russian adaptation with Learned Embedding Propagationcited by 8
- 2024Multilingual Arbitrage: Optimizing Data Pools to Accelerate Multilingual Progresscited by 6
- 2024Adapting Chat Language Models Using Only Target Unlabeled Language Datacited by 6
- 2024From English-Centric to Effective Bilingual: LLMs with Custom Tokenizers for Underrepresented Languagescited by 5
- 2026Stop Taking Tokenizers for Granted: They Are Core Design Decisions in Large Language Modelscited by 5
- 2024Why We Build Local Large Language Models: An Observational Analysis from 35 Japanese and Multilingual LLMscited by 4
- 2025Evaluation of LLMs in Medical Text Summarization: The Role of Vocabulary Adaptation in High OOV Settingscited by 4
- 2025Mitigating Catastrophic Forgetting in Target Language Adaptation of LLMs via Source-Shielded Updatescited by 4
12 most cited of 22 All 22 (JSON)
- 2026To Each Language Its Tokenizer: Modular Tokenizers for Efficient Multilingual LLMs14 Sep 2026
- 2026From Zero to Hero: An Open LLM Ecosystem for Armenian3 Sep 2026
- 2026Reading the News: Adapting Large Language Models to Swedish Journalism Through Continued Pre-Training31 Aug 2026
- 2026MultiHashFormer: Hash-based Generative Language Models26 Jun 2026
- 2026How Does "English (US)" Become the Default? Triangulating Structural Bias Towards American English Across the LLM Pipeline5 Apr 2026
- 2026Stop Taking Tokenizers for Granted: They Are Core Design Decisions in Large Language Models19 Jan 2026
- 2025Mitigating Catastrophic Forgetting in Target Language Adaptation of LLMs via Source-Shielded Updates4 Dec 2025
- 2025Teaching Old Tokenizers New Words: Efficient Tokenizer Adaptation for Pre-trained Models3 Dec 2025
- 2025Vocabulary Customization for Efficient Domain-Specific LLM Deployment30 Sep 2025
- 2025Prompt, Translate, Fine-Tune, Re-Initialize, or Instruction-Tune? Adapting LLMs for In-Context Learning in Low-Resource Languages23 Jun 2025
- 2025Evaluation of LLMs in Medical Text Summarization: The Role of Vocabulary Adaptation in High OOV Settings27 May 2025
- 2025Improving Multilingual Capabilities with Cultural and Local Knowledge in Large Language Models While Enhancing Native Performance13 Apr 2025
12 newest of 22 All 22 (JSON)