Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The LaunchParams interface of the Launch Handler API is used when implementing custom launch navigation handling in a PWA. When window.launchQueue.setConsumer() is invoked to set up the launch navigation handling functionality, the callback function inside setConsumer() is passed a LaunchParams object instance.

Such custom navigation handling is initiated via Window.launchQueue when a PWA has been launched with a launch_handler client_mode value of focus-existing, navigate-new, or navigate-existing.

Instance properties

LaunchParams.files Read only Experimental

Returns a read-only array of FileSystemHandle objects representing any files passed along with the launch navigation via the POST method.

LaunchParams.targetURL Read only Experimental

Returns the target URL of the launch.


if ("launchQueue" in window) {
  window.launchQueue.setConsumer((launchParams) => {
    if (launchParams.targetURL) {
      const params = new URL(launchParams.targetURL).searchParams;

      // Assuming a music player app that gets a track passed to it to be played
      const track = params.get("track");
      if (track) {
        audio.src = track;
        title.textContent = new URL(track).pathname.substr(1);;


Web App Launch Handler API
# launchparams-interface

Browser compatibility

BCD tables only load in the browser

See also