FAQ

NLP

Multilingual and translation datasets

Parallel corpora, multilingual web text and the low-resource language problem — what is available and how uneven it is.

Multilingual data is abundant for a dozen languages and thin for the rest, and that unevenness is the defining feature of the category rather than an incidental gap.

Two shapes serve different purposes. Parallel corpora pair the same content across languages and train translation directly. Multilingual monolingual corpora — large text collections in many languages, not aligned — are what you use for continued pretraining to give a model competence in a language it barely saw.

The distribution is steeply skewed. The large multilingual web corpora typically cover five to a few dozen languages well, and the published token counts drop by orders of magnitude outside the top handful. If you work in a genuinely low-resource language, expect the realistic options to be religious texts, government publications, Wikipedia and whatever you can assemble yourself — which is a different scale of project from fine-tuning in a well-served language, and worth scoping honestly before committing.

A diagram of the XTREME benchmark laid out as a central hub with branches to four task families - sentence classification, structured prediction, question answering and sentence retrieval - and the named datasets under each, all feeding into one combined score.
What a cross-lingual benchmark actually covers, task by task: nine datasets in four task families, averaged into one combined score. A single score hides which tasks, and which languages, a model is weak on. Image: google-research/xtreme · Apache-2.0 repository · from “XTREME: A Massively Multilingual Multi-task Benchmark for Evaluating Cross-lingual Generalization”, arXiv:2003.11080
DatasetModalitySizeLicenceBest for
FLORES+: Multilingual Translation BenchmarkText2,000 sentencesCC BY-SA 4.0Translation models
English—French Parallel Translation DatasetText22,500,000 sentencesODbLHigh-performance machine translation
EXAMS - Multilingual school exam questionsText24,000 questionsCC BY-SA 4.0Multilingual question answering
WIT BaseMultimodal6.5M examplesCC BY-SA 3.0Combine images and text
WMT SQM Human EvaluationText109,600 examplesApache 2.0Machine translation quality
FineWeb2 Edu JapaneseText120M textsODC-ByJapanese language models
FineFrench v1Text125M documentsODC-ByFrench language models
VietVault: Large-Scale Vietnamese CorpusText80 GBODC-ByVietnamese language models
Licences in this shortlist — computed from the 8 datasets below. Amber marks non-commercial, share-alike or mixed terms.
A cropped Wikipedia article for Half Dome with red boxes and labels marking the fields WIT extracts: the page title 'Half Dome', the page description paragraph beginning 'Half Dome is a granite dome at the eastern end of Yosemite Valley', the infobox photograph of Half Dome at sunset, and its caption 'Sunset over Half Dome from Glacier Point' labelled as the reference description.
Where a WIT example comes from: a page title, the page's opening description, an image and the caption under it, all taken from one Wikipedia article. Repeated across 108 language editions, this is how WIT has captions in many languages, written by each edition's own editors. Image (cropped): google-research-datasets/wit · CC BY-SA 3.0 (dataset repository); photo CC BY-SA 3.0 by David Iliff · from “WIT: Wikipedia-based Image Text Dataset for Multimodal Multilingual Machine Learning”, arXiv:2103.01913 · Photo: David Iliff, CC BY-SA 3.0; this crop is offered under CC BY-SA 3.0
№ 01

FLORES+: Multilingual Translation Benchmark

Text
Size
Approximately 2,000 sentences per language × 230 language varieties, structured text format
Licence
CC-BY-SA 4.0

Roughly 2,000 parallel sentences per language across 230 language varieties, drawn from Wikinews, Wikivoyage and Wikijunior. One of the widest-coverage open translation benchmarks, and multi-way parallel: every language shares the same source sentences.

What to train on it

Evaluating translation models on low- and high-resource languages, testing multilingual systems in a controlled setting, and exploring LLM or NMT language coverage.

Source: innovatiana.com

№ 02

English—French Parallel Translation Dataset

Text
Size
~22,500,000 aligned sentences, text format (TSV/CSV) two columns (English/French)
Licence
Open Database License (ODbL) or equivalent

About 22.5 million aligned English-French sentence pairs in two-column TSV or CSV, gathered by web collection and used as the basis for the 2015 Workshop on Statistical Machine Translation. Very large for a single language pair.

What to train on it

Training high-performance machine translation, fine-tuning multilingual LLMs for translation or bilingual generation, and studying corpus alignment methods.

Source: innovatiana.com

№ 03

EXAMS - Multilingual school exam questions

Text
Size
More than 24,000 questions in 16 languages and 24 subjects (136,082 rows across overlapping configurations)
Licence
CC BY-SA 4.0

More than 24,000 high school exam questions across 16 languages and 24 subjects, including mathematics, biology, history and geography (row counts in the Hugging Face release are higher because its configurations overlap), with some items supplying context and answer choices. Real exam material rather than crowd-written questions.

What to train on it

Training multilingual question answering, evaluating cross-language generalisation, and testing educational models in a realistic context.

Source: innovatiana.com

A bar chart with one blue bar per FLORES-200 language, sorted by quality score from left to right, crossed by a white band labelled 90% quality standard. Arrows label Chokwe, Limburgish, Crimean Tatar, Bemba, Central Aymara, Kabiyè and Central Kanuri (Arabic script).
Quality-assurance scores for the human translations in FLORES-200, one bar per language, against the 90% minimum standard (the white line). Every language clears it, but the margin varies, from Chokwe just above the line to Central Kanuri in Arabic script at the top. Before trusting a shared benchmark for a low-resource language, check how its test sentences were checked. Image: Fig. 2 of the article · CC BY 4.0 · from NLLB Team 2024, Nature, “Scaling neural machine translation to 200 languages”, doi:10.1038/s41586-024-07335-x
№ 04

WIT Base

Multimodal
Size
About 6.5 million examples (6,477,255; the dataset viewer previews only the first 5.15 GB, about 108,000 rows), multilingual images and captions, Parquet format
Licence
CC BY-SA (upstream WIT is CC BY-SA 3.0)

About 6.5 million Wikipedia image-and-caption examples in Parquet (the viewer previews only the first 5.15 GB, about 108,000 rows), with captions in many languages. Wikimedia provenance makes it one of the cleanest multilingual image-text sources available.

What to train on it

Training models that combine images and text across several languages, improving multimodal translation and image description, and testing robustness on real-world data.

Source: innovatiana.com

№ 05

WMT SQM Human Evaluation

Text
Size
About 109,600 human evaluation examples (109,605 rows)
Licence
Apache 2.0

About 109,600 human DA+SQM annotations scoring machine translation quality from the WMT 2022 task, each with source text, translation, reference, score and metadata such as language pair, domain and year.

What to train on it

Evaluating machine translation quality, analysing inter-annotator variability and stabilising scores, and comparing MT models across domains and languages.

Source: innovatiana.com

EXAMSdata/exams/multilingual · test.jsonl, six parallel questions
languagestemchoicesanswerKey
GermanDer durchschnittliche Salzgehalt des Meerwassers:A 35% · B 35‰ · C 30‰ · D 30%B
FrenchLe taux moyen de salinité de l’eau de la mer :A 30% · B 30‰ · C 35% · D 35‰D
ItalianLa media della concentrazione del sale nell’acqua marina è:A 35‰ · B 30% · C 35% · D 30‰A
SpanishContenido promedio de sal del agua de mar.A 30‰ · B 30% · C 35‰ · D 35%C
CroatianProsječni salinitet morske vode:A 30% · B 30‰ · C 35% · D 35‰D
HungarianA tengervíz átlagos sótartalma:A 30‰ · B 35‰ · C 30% · D 35%B
The same grade-12 geography question in six of EXAMS's languages, linked by the dataset's own parallel-question file. The choices are shuffled per language, so the correct letter changes from row to row while the answer stays 35‰ — a model can't carry a letter across translations. From the dataset: mhardalov/exams-qa · data/exams/multilingual · CC BY-SA 4.0
№ 06

FineWeb2 Edu Japanese

Text
Size
Approximately 120 million texts (~89.3 billion tokens), text format, subsets in Parquet format
Licence
Open Data Commons Attribution License (ODC-by) v1.0

Roughly 120 million Japanese web texts totalling about 89.3 billion tokens, with subsets in Parquet, filtered for educational value so that most web noise is removed. The Japanese counterpart to FineWeb-Edu.

What to train on it

Training and evaluating Japanese language models for education and comprehension, improving LLMs for learning assistants, and studying large-scale web text filtering.

Source: innovatiana.com

№ 07

FineFrench v1

Text
Size
About 125 million documents (some 66 million rated high quality), JSONL/parquet format, 283 GB
Licence
ODC-by 1.0

About 125 million French-language web documents from FineWeb-2 in JSONL and Parquet (283 GB), of which a CamemBERT classifier trained on GPT-4o labels rates some 66 million as high quality and flags the rest. A FineWeb-style corpus for French.

What to train on it

Training French language models, experimenting with automated web text cleaning, and serving as a base for semantic analysis, summarisation or content classification.

Source: innovatiana.com

№ 08

VietVault: Large-Scale Vietnamese Corpus

Text
Size
80GB of text, raw Markdown format (UTF-8), line per document
Licence
ODC-by

80 GB of Vietnamese text in raw UTF-8 Markdown, one document per line, built from Common Crawl between 2013 and 2023 then cleaned, deduplicated and filtered for toxic content. Unannotated, intended for pre-training.

What to train on it

Pre-training Vietnamese language models such as BERT, RoBERTa or GPT, fine-tuning on classification, NER or summarisation, and modelling modern Vietnamese.

Source: innovatiana.com

A step-like line chart: x axis, percent of language corpora in the dataset (0 to 100); y axis, percent correct or less (0 to 100); lines for CCAligned, ParaCrawl, WikiMatrix, OSCAR and mC4, with WikiMatrix and CCAligned lowest across most of the range.
From a manual audit of sentence samples: what share of each corpus's languages falls at or below a given percentage of correct sentences. Half of CCAligned's audited languages are at or below about 35% correct and half of WikiMatrix's at or below about 15%; even ParaCrawl, OSCAR and mC4 have a tail of languages below 50%. Image: Figure 1 of the paper · CC BY 4.0 · from “Quality at a Glance: An Audit of Web-Crawled Multilingual Datasets”, arXiv:2103.12028

How this list was put together

Drawn from the datasets in Dataset Finder filed under this topic, then checked by hand against what this page covers. A tag is a filing decision, not a description, so records that carried the tag without being about the topic were removed, and relevant records filed elsewhere were added. The order puts the closest fit first.

Sizes and licences come from each dataset's own documentation, vague wording included. Where we found a re-upload or catalogue card stating a licence that the original release contradicts — a CC0 tag on Flickr photographs, MIT on data whose terms require a signed agreement — the entry gives the original terms and says so. The comparison table abbreviates licences; hover a cell for the full wording.

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