JavaScript logging with JSNLog
JSNLog (jsnlog.com) lets you log JavaScript exceptions, AJAX timeouts and other JavaScript events on the client. The log items are sent automatically to the server where they are stored in your server side logs.
Versions for .Net and Node. .Net version supports Log4Net, NLog, Elmah, Serilog and Common.Logging. Node version supports Winston transports.
Lots of features to log all the info you need, but only when you need it, and without the info you don't need.