HPLT3-PerRef: A Refined Large-Scale Persian Web Corpus via Supervised Document Quality Filtering

Alireza Razzaghi, Tomasz Galica, Erik Henriksson, Veronika Laippala


Abstract
Large-scale web corpora are valuable resources for natural language processing (NLP), linguistic research, and language model training, particularly for digitally low-resource languages such as Persian. However, web-derived text often contains document-level noise, even after quality-filtering pipelines. We present HPLT3 Persian Refined (HPLT3-PerRef), a refined Persian web corpus containing 105.9 billion tokens and 102.37 million documents, obtained by applying a supervised quality-filtering pipeline to the Persian subset of HPLT3. We manually annotated 6,144 Persian web documents and trained a multilingual transformer-based classifier to distinguish high- and low-quality documents. The classifier removed approximately 20% of the original corpus while preserving broad domain coverage and complements HPLT3’s heuristic-based Web Document Score (WDS) by identifying additional low-quality documents. We publicly release the corpus, the trained classifier, and the complete source code.
Anthology ID:
2026.wac-1.6
Volume:
Proceedings of the 13th Web-as-Corpus Workshop
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pedro Ortiz Suarez, Laurie Burchell, Nikola Ljubešić, Yves Scherrer, Veronika Laippala, Vuk Dinić, Thom Vaughan
Venues:
WAC | WS
SIG:
SIGWAC
Publisher:
Association for Computational Linguistics
Note:
Pages:
60–69
Language:
URL:
https://aclanthology.org/2026.wac-1.6/
DOI:
Bibkey:
Cite (ACL):
Alireza Razzaghi, Tomasz Galica, Erik Henriksson, and Veronika Laippala. 2026. HPLT3-PerRef: A Refined Large-Scale Persian Web Corpus via Supervised Document Quality Filtering. In Proceedings of the 13th Web-as-Corpus Workshop, pages 60–69, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HPLT3-PerRef: A Refined Large-Scale Persian Web Corpus via Supervised Document Quality Filtering (Razzaghi et al., WAC 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.wac-1.6.pdf