I can confidently say there are some fantastic platforms for reading them online for free. One of my go-to sites is WuxiaWorld, which offers a massive collection of translated Chinese martial arts novels with high-quality translations. They have everything from classic Jin Yong works like 'The Legend of the Condor Heroes' to newer web novels. Another great option is Novel Updates, which aggregates chapters from various translators and provides links to the original sources.
For those who prefer Vietnamese translations, I often visit TruyenYY or TangThuVien, which have extensive libraries of wuxia and xianxia stories. These sites are regularly updated and have active communities discussing the latest chapters. If you're looking for mobile accessibility, the app Webnovel has a decent free section with many martial arts titles, though some premium content requires payment. The key is to explore different platforms to find which interface and translation style suits your reading preferences best.