pangu.js
A JavaScript library, with ports in several other languages, that automatically inserts spacing between Chinese, Japanese or Korean text and adjacent Latin letters, numbers and symbols, plus a browser extension that applies it to web pages.
pangu.js is a text-spacing library that inserts whitespace between CJK (Chinese, Japanese, Korean) characters and adjacent alphabetic letters, numbers and symbols, following the convention of always spacing full-width and half-width characters apart. It ships as an npm package with a browser build that includes DOM-aware helpers for spacing a whole page or a single node.
A companion Chrome extension applies the same spacing rules to any page as you browse, and adds an optional AI Spacing mode that resolves ambiguous symbols, such as a plus sign meaning "and" versus "or more," by asking a small on-device language model that runs fully offline in the browser. The underlying spacing rules are also implemented as ports in Python, Go, Java, Rust, PHP, Ruby, Swift, Clojure, Dart, Elixir and Objective-C.