Measuring Online Hate on 4chan using Pre-trained Deep Learning Models

-- Online hate speech can harmfully impact individuals and groups, specifically on non - moderated platforms such as 4chan where users can post anonymous content. This work focuses on analy s ing and measuring the prevalence of online hat e on 4chan's politically incorrect board (/pol/) using state - of - the - art Natural Language Processing (NLP) models, specifically transformer - based models such as RoBERTa and Detoxify . By leveraging these advanced models, we provide an in - depth analysis of hate speech dynamics and quantify the extent of online hate non - moderated platforms. The study advances understanding through multi - class classification of hate speech (racism, sexism, religion, etc.), while also incorporating the classification of toxic content (e.g., identity attacks and threats) and a further topic modelling analysis. The results show that 11.20% of this dataset is identified as containing hate in different categories. These evaluations show that online hate is manifested in various forms, confirming the complicated and volatile nature of detection in the wild. Index Terms -- Hate speech, machine learning, natural language processing (NLP), online hate, toxicity analysis. INTRODUCTION H E SPREAD of hate speech on online platforms has become a serious problem in our society. As digital communication becomes ubiquitous, platforms like 4chan, known for their anonymity and minimal moderation, have become hotspots for this harmful behaviour . This is particularly evident on its politically incorrect board, /pol/, a notorious board dedicated to discussing politics and current events, often associated with hate speech, extremist content, and conspiracy theories [1] . The anonymity provided by these platforms often encourages users to express extreme ideologies [2] . This issue raises significant concerns about the impact on at - risk and vulnerable groups as it can cause real - world harm, including psychological trauma. Therefore, a systematic approach is needed to measure and understand the prevalence and forms of online hate. Received 28 August 2024; revised 23 December 2024, 10 February 2025, and 6 March 2025; accepted 6 March 2025. This work is supported by the UK Research and Innovation (UKRI), through the Strategic Priority Fund as part of the Protecting Citizens Online programme (AGENCY: Assuring Citizen Agency in a World with Complex Online Harms, EP/W032481/2).