Navigation: canGoBack property
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
  The canGoBack read-only property of the
  Navigation interface returns true
  if it is possible to navigate backwards in the navigation history
  (i.e. the currentEntry is
  not the first one in the history entry list),
  and false if it is not.
Value
A boolean value: true if it is possible to navigate backwards in the navigation history, false otherwise.
Examples
js
async function backHandler() {
  if (navigation.canGoBack) {
    await navigation.back().finished;
    // Handle any required clean-up after
    // navigation has finished
  } else {
    displayBanner("You are on the first page");
  }
}
async function forwardHandler() {
  if (navigation.canGoForward) {
    await navigation.forward().finished;
    // Handle any required clean-up after
    // navigation has finished
  } else {
    displayBanner("You are on the last page");
  }
}
Specifications
| Specification | 
|---|
| Unknown specification  # dom-navigation-cangoback  | 
Browser compatibility
BCD tables only load in the browser