The World Wide Web has evolved from a resource for building linguistic corpora into the central data infrastructure powering modern natural language processing and Large Language Models (LLMs). As web-scale data increasingly shapes AI systems’ knowledge and capabilities, understanding its quality, representativeness, and ethical implications has become critical.

At the same time, the “more is better” paradigm is being challenged by issues such as machine-generated content, data toxicity, limited metadata, and the under-representation of many languages and domains. These challenges call for a shift toward Data-Centric AI, focusing on the curation, analysis, and responsible use of web-derived data.

The 13th Web-as-Corpus (WaC-13) workshop provides a multidisciplinary forum for research addressing the full lifecycle of web data. We invite submissions on methods, resources, and applications related to web corpora, with special emphasis on multilingual data and less-resourced languages.

Topics of interest include (but are not limited to):

* Creation and evaluation of high-quality datasets for foundation models (e.g., data collection, filtering, enrichment, language identification)
* Use of web data in empirical linguistic research
* Analysis of web-scale corpora for quality, representativeness, and societal insights
* Ethical and legal aspects of collecting, sharing, and using web data

By bringing together researchers from NLP, linguistics, and the social sciences, WaC aims to advance best practices for one of the field’s most influential data sources.