The best replacement for postback is callback.

The best alternatives to postback are rated as following:
★★★★★  callback
★★★  submit
★★  response.redirect
★★  post
★  refresh
★  server.transfer
  asynchronous postback
  partial postback

Your alternative for postback is not listed? Suggest!
Speaking about postback, one probably shouldn't forget about updatepanel.

Other search terms related to postback and their ratings are:
★★★★★ updatepanel
★★★★ ajax
★★★★ refresh
★★★ refreshing page
★★ refresh asp.net
★★ querystring
★★ validation
★★ modalpopupextender
★★ page load
★ page refreshing
★ master page
★ anchor tag
★ refresh asp net
★ button
★ html button
refresh javascript
asp
hyperlink
You have in mind a companion for postback and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of postback in all years. Click on graph for more.
postback
callback
submit