Sometimes these maps can be kinda hard to find when navigating their pages so I have made a post for you guys to easily find them when looking for service in your area. If the link is dead, flag the post as ‘something else’ and state so. Refer to this page if needed in other posts.
Taiwan Mobile - 臺灣大哥大
Click UMTS for 3G
Chunghwa Telecom Emome - 中華電信
Self explanatory which one is 3G and which is 4G and 5G.
Fareastone - 遠傳電信
https://ecare.fetnet.net/DigService/serviceCoverageController/serviceCoveragePage
UMTS is 3G. Not sure what 語言涵蓋 means. 4.5G+5G should be self explanatory.
Asia Pacific Telecom GT4G - 亞太電信
This selection switches between 4G and 5G.
Taiwan Star, Formerly Vibo - 臺灣之星, 原威寶
Click this to turn on the colour overlay.
Click this for 3G colour overlay.