SalamandraTA-7b-instruct-WMT25 is an expanded version of SalamandraTA-7B-Instruct specifically created for the WMT25 General Translation Shared Task submission and released solely for non-commercial research purposes.
This version of SalamadraTA has undergone an additional continual pre-training round aimed at expanding the language coverage of the model, and include the additional languages featured in the WMT 2025 shared task that were not supported by the previous version of SalamandraTA-7B-Instruct. It has also undergone an extra instruction fine-tuning step.
Note that we additionally included the English-to-Hindi direction, in order to support better transfer for related languages such as Bhojpuri.
To extend the language coverage, we performed vocabulary adaptation by training from scratch a new tokenizer on a corpus that includes the original languages, along with additional monolingual text for the seven new languages not present in the original SALAMANDRA tokenizer.
For further details, we refer to our paper which is due to be published in August 2025.
[!WARNING]
DISCLAIMER: This version of Salamandra is tailored exclusively for translation tasks. It lacks chat capabilities and has not been trained with any chat instructions.
Model Details
Architecture
Total Parameters
7,768,117,248
Embedding Parameters
1,048,576,000
Layers
32
Hidden size
4,096
Attention heads
32
Context length
8,192
Vocabulary size
256,000
Precision
bfloat16
Embedding type
RoPE
Activation Function
SwiGLU
Layer normalization
RMS Norm
Flash attention
✅
Grouped Query Attention
✅
Num. query groups
8
Intended Use
Direct Use
The Model can be used in any of the languages included in the training data for general machine translation tasks.
The model is released under a Research-Only License that regulates its use. By accessing or using the Model, you acknowledge that you have read, understood, and agree to be bound by the terms below.
1. Purpose
The Model is provided solely for non-commercial research purposes. This includes academic research, experimentation, benchmarking, and publication of research results.
2. Restrictions
You may not:
Use the Model or any derivative works for commercial purposes, including offering it as a service or integrating it into commercial products.
Use the Model to intentionally generate or disseminate harmful, deceptive, or unlawful content.
Use the Model in a manner that violates applicable laws, regulations, or the rights of others.
Attempt to relicense, sell, or redistribute the Model outside the scope of this License.
3. Derivative Works
You may create modifications or derivative works of the Model for research purposes only. Any such works must be released under terms that are at least as restrictive as this License.
4. Attribution
Any publications, reports, or other outputs obtained by using the Model must acknowledge "SalamandraTA-7b-instruct-WMT25, released under a Research-Only License by MT Group, Language Technologies Lab, Barcelona Supercomputing Center, 2025."
5. No Warranty
The Model is provided "as is", without warranties of any kind, express or implied, including but not limited to accuracy, safety, or fitness for a particular purpose.
6. Limitation of Liability
The Licensor is not responsible for any damages arising from the use or inability to use the Model.
7. Termination
This License will terminate automatically if you fail to comply with any of its terms. Upon termination, you must cease all use of the Model and destroy any copies in your possession.
Hardware and Software
Training Framework
SalamandraTA-7b-base was continually pre-trained using NVIDIA’s NeMo Framework,
which leverages PyTorch Lightning for efficient model training in highly distributed settings.
SalamandraTA-7b-instruct was produced with FastChat.
Compute Infrastructure
All models were trained on MareNostrum 5, a pre-exascale EuroHPC supercomputer hosted and
operated by Barcelona Supercomputing Center.
The accelerated partition is composed of 1,120 nodes with the following specifications:
4x Nvidia Hopper GPUs with 64GB HBM2 memory
2x Intel Sapphire Rapids 8460Y+ at 2.3Ghz and 32c each (64 cores)
4x NDR200 (BW per node 800Gb/s)
512 GB of Main memory (DDR5)
460GB on NVMe storage
How to use
You can use this model to translate in the following directions:
Czech to Ukrainian
Czech to German
Japanese to Chinese (Simplified)
English to Arabic
English to Bhojpuri
English to Chinese (Simplified)
English to Czech
English to Estonian
English to Icelandic
English to Italian
English to Japanese
English to Korean
English to Russian
English to Serbian (Latin script)
English to Ukrainian
The instruction-following model uses the commonly adopted ChatML template:
The easiest way to apply it is by using the tokenizer's built-in functions, as shown in the following snippet.
python
1from datetime import datetime
2from transformers import AutoTokenizer, AutoModelForCausalLM
3import transformers
4import torch
56model_id ="LangTech-MT/salamandraTA-7b-instruct-WMT25"78# Map from human-readable names to model language labels9lang_map ={10'English':'English'11'Czech':'Czech',12'Ukrainian':'Ukrainian',13'German':'German',14'Japanese':'Japanese',15'Chinese':'Chinese',16'English':'English',17'Arabic':'Arabic',18'Bhojpuri':'Bhojpuri',19'Estonian':'Estonian',20'Icelandic':'Icelandic',21'Italian':'Italian',22'Korean':'Korean',23'Russian':'Russian',24'Serbian':'Serbian_Latin'25}2627# Input parameters28source ='English'29target ='Japanese'30sentence ="Once when I was six years old I saw a magnificent picture in a book."3132# Map to model's expected language names33source_lang = lang_map[source]34target_lang = lang_map[target]3536text =f"Translate the following text from {source_lang} into {target_lang}.\n{source_lang}: {sentence} \n{target_lang}:"3738# Load tokenizer and model39tokenizer = AutoTokenizer.from_pretrained(model_id)4041model = AutoModelForCausalLM.from_pretrained(42 model_id,43 device_map="auto",44 torch_dtype=torch.bfloat16
45)4647# Construct prompt using chat template48message =[{"role":"user","content": text }]49date_string = datetime.today().strftime('%Y-%m-%d')5051prompt = tokenizer.apply_chat_template(52 message,53 tokenize=False,54 add_generation_prompt=True,55 date_string=date_string
56)5758inputs = tokenizer.encode(prompt, add_special_tokens=False, return_tensors="pt")59input_length = inputs.shape[1]6061# Generate output62outputs = model.generate(63 input_ids=inputs.to(model.device),64 max_new_tokens=400,65 early_stopping=True,66 num_beams=567)6869# Decode and print output70print(tokenizer.decode(outputs[0, input_length:], skip_special_tokens=True))71# 6歳の時、ある本で素晴らしい絵を見たことがある。
Using this template, each turn is preceded by a <|im_start|> delimiter and the role of the entity
(either user, for content supplied by the user, or assistant for LLM responses), and finished with the <|im_end|> token.
Machine Translation Prompt
You can use the following prompt template:
Translate the following text from {source} into {target}.
{source}: {source sentence}
{target}:
Show an example
python
1source ='English'2target ='Japanese'3source_sentence ="Once when I was six years old I saw a magnificent picture in a book."45text =f"Translate the following text from {source} into {target}.\n{source}: {source_sentence} \n{target}:"6# 6歳の時、ある本で素晴らしい絵を見たことがある。
Data
Pretraining data
We first conducted continual pretraining on SalamandraTA-7B, focusing on expanding coverage to include additional language pairs featured in the WMT 2025 shared task.
This stage included 393,507,678 sentence pairs across 14 languages and 15 translation directions, totaling approximately 27 billion tokens.
For the language pairs featured in the WMT 2025 shared task, we primarily used data sourced from the WMT 2025 Translation Task Training Data.
To mitigate the risk of catastrophic forgetting, we subsampled 20M sentences for directions already covered during the continual pretraining of SalamandraTA-7B-Instruct (EN→CS, EN→ET, EN→RU, EN→UK).
For English-to-Serbian (Latin script), we combined two sources from the continual pretraining of SalamandraTA-7B-Instruct:
English–Serbian (Latin script) data
English–Serbian (Cyrillic script) data, which we converted to Latin script using rule-based transliteration
We also included the English-to-Hindi direction, which is not part of this year’s shared task, to support transfer learning for related Indic languages such as Bhojpuri.
English-to-Hindi data was sourced from multiple corpora hosted by OPUS.
Click the expand button below to see the full list of language pairs and the data sources included in the pretraining.
Aulamo, M., Sulubacak, U., Virpioja, S., & Tiedemann, J. (2020). OpusTools and Parallel Corpus Diagnostics. In N. Calzolari, F. Béchet, P. Blache, K. Choukri, C. Cieri, T. Declerck, S. Goggi, H. Isahara, B. Maegaard, J. Mariani, H. Mazo, A. Moreno, J. Odijk, & S. Piperidis (Eds.), Proceedings of the Twelfth Language Resources and Evaluation Conference (pp. 3782–3789). European Language Resources Association. https://aclanthology.org/2020.lrec-1.467
de Gibert, O., Nail, G., Arefyev, N., Bañón, M., van der Linde, J., Ji, S., Zaragoza-Bernabeu, J., Aulamo, M., Ramírez-Sánchez, G., Kutuzov, A., Pyysalo, S., Oepen, S., & Tiedemann, J. (2024). A new massive multilingual dataset for high-performance language technologies. In N. Calzolari, M.-Y. Kan, V. Hoste, A. Lenci, S. Sakti, & N. Xue (Eds.), Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024) (pp. 1116–1128). Torino, Italia: ELRA and ICCL.
NLLB Team, Costa-jussà, M. R., Cross, J., Çelebi, O., Elbayad, M., Heafield, K., Heffernan, K., Kalbassi, E., Lam, J., Licht, D., Maillard, J., Sun, A., Wang, S., Wenzek, G., Youngblood, A., Akula, B., Barrault, L., Mejia Gonzalez, G., Hansanti, P., Hoffman, J., Jarrett, S., Sadagopan, K. R., Rowe, D., Spruit, S., Tran, C., Andrews, P., Ayan, N. F., Bhosale, S., Edunov, S., Fan, A., Gao, C., Goswami, V., Guzmán, F., Koehn, P., Mourachko, A., Ropers, C., Saleem, S., Schwenk, H., & Wang, J. (2022). No language left behind: Scaling human-centered machine translation (No. arXiv: 2207.04672). arXiv. https://arxiv.org/abs/2207.04672
Ramesh, G., Doddapaneni, S., Bheemaraj, A., Jobanputra, M., AK, R., Sharma, A., Sahoo, S., Diddee, H., Mahalakshmi, J., Kakwani, D., Kumar, N., Pradeep, A., Nagaraj, S., Deepak, K., Raghavan, V., Kunchukuttan, A., Kumar, P., & Khapra, M. S. (2022). Samanantar: The largest publicly available parallel corpora collection for 11 Indic languages. Transactions of the Association for Computational Linguistics, 10, 145–162. https://doi.org/10.1162/tacl_a_00461
Schwenk, H., Wenzek, G., Edunov, S., Grave, E., & Joulin, A. (2020). CCMatrix: Mining Billions of High-Quality Parallel Sentences on the WEB (No. arXiv:1911.04944). arXiv. https://doi.org/10.48550/arXiv.1911.04944
Instruction Tuning Data
This model has been fine-tuned on ~51k instructions, primarily targeting machine translation performance for the languages pairs featured in the WMT 2025 shared task.
The corpus used for the instruction tuning round was built to focus on paragraph-level translation, context-aware machine translation, and sentence-level translation.
To construct paragraph-level data, we source from Flores+200 dev, NTREX, and News-Commentary.
The paragraph-level data were constructed by concatenating adjacent sentences (randomly grouping 2, 3, or 4) from the same article or document in Flores+200 dev, NTREX, and News Commentary.
Serbian Cyrillic data from FLORES-dev was transliterated into Serbian Latin.
In addition, we included data from TowerBlocks that we considered relevant to our tasks.
Click the expand button below to see the full list of tasks included in the finetuning data.
Alves, D. M., Pombal, J., Guerreiro, N. M., Martins, P. H., Alves, J., Farajian, A., Peters, B., Rei, R., Fernandes, P., Agrawal, S., Colombo, P., de Souza, J. G. C., & Martins, A. F. T. (2024). Tower: An open multilingual large language model for translation-related tasks. arXiv. https://arxiv.org/abs/2402.17733
Federmann, C., Kocmi, T., & Xin, Y. (2022). NTREX-128 – News test references for MT evaluation of 128 languages. Proceedings of the First Workshop on Scaling Up Multilingual Evaluation, 21–24. Association for Computational Linguistics. https://aclanthology.org/2022.sumeval-1.4
Detailed information on the work done to examine the presence of unwanted social and cognitive biases in the base model can be found
at Salamandra-7B model card.
No specific analysis has yet been carried out in order to evaluate potential biases or limitations in translation
accuracy across different languages, dialects, or domains. However, we recognize the importance of identifying and addressing any harmful stereotypes,
cultural inaccuracies, or systematic performance discrepancies that may arise in Machine Translation. As such, we plan to continue performing more analyses
as we implement the necessary metrics and methods within our evaluation framework MT-Lens.
Note that the model has only undergone preliminary instruction tuning.
We urge developers to consider potential limitations and conduct safety testing and tuning tailored to their specific applications.
Additional information
Author
The Language Technologies Unit from Barcelona Supercomputing Center.
Contact
For further information, please send an email to langtech@bsc.es.
Copyright
Copyright(c) 2025 by Language Technologies Unit, Barcelona Supercomputing Center.
Funding
This work is funded by the Ministerio para la Transformación Digital y de la Función Pública - Funded by EU – NextGenerationEU within the framework of the project Modelos del Lenguaje.
This work has been promoted and financed by the Government of Catalonia through the Aina project.
This work is funded by the Ministerio para la Transformación Digital y de la Función Pública - Funded by EU – NextGenerationEU within the framework of the project ILENIA with reference 2022/TL22/00215337.
Disclaimer
Be aware that the model may contain biases or other unintended distortions.
When third parties deploy systems or provide services based on this model, or use the model themselves,
they bear the responsibility for mitigating any associated risks and ensuring compliance with applicable regulations,
including those governing the use of Artificial Intelligence.
The Barcelona Supercomputing Center, as the owner and creator of the model, shall not be held liable for any outcomes resulting from third-party use.