What is japanese-text-cleaner?

Japanese Text Cleaner is a web application that automatically tidies up messy Japanese text. Japanese text often arrives from different sources in inconsistent formats, mixed full-width and half-width characters, inconsistent quotation marks, unusual line breaks, HTML tags, and encoding problems (Japanese text can be stored in several different character encodings like UTF-8, Shift-JIS, or EUC-JP). This tool standardizes all of that automatically. It runs a 16-step pipeline over the text: normalizing the Unicode representation, converting character widths, standardizing punctuation and brackets, removing unwanted control characters, fixing quote pairings, and reformatting line breaks so that each sentence sits on its own line. There are three cleaning modes, deep, standard, and light, depending on how aggressively you want to transform the text. You can paste text directly, drag and drop multiple text files for batch processing, and export the results as a zip archive. It also exposes an API endpoint so AI tools or natural language processing pipelines can send text for cleaning programmatically. This is useful for anyone preparing Japanese text data for analysis, translation, or AI training.