There is typically a quick transpile process in the IDE/toolchain of your choice. Most browser dev tools now support sourcemaps quite well which means that debugging shows the TS source and breakpoints are set directly there and typically show error stacktraces with your TS files.

Another option is to load Typescript in your browser and let it transpile directly in the browser. Sourcemaps in this case are a bit more iffy in their browser support, but it can be an option for a quick debug cycle if you wanted to try something like that. Not particularly the fastest idea for a production app, though.