How to get a list of all files in Cloud Storage in a Firebase app?

As of May 2019, version 6.1.0 of the Firebase SDK for Cloud Storage now supports listing all objects from a bucket. You simply need to call listAll() in a Reference:

    // Since you mentioned your images are in a folder,
    // we'll create a Reference to that folder:
    var storageRef = firebase.storage().ref("your_folder");


    // Now we get the references of these images
    storageRef.listAll().then(function(result) {
      result.items.forEach(function(imageRef) {
        // And finally display them
        displayImage(imageRef);
      });
    }).catch(function(error) {
      // Handle any errors
    });

    function displayImage(imageRef) {
      imageRef.getDownloadURL().then(function(url) {
        // TODO: Display the image on the UI
      }).catch(function(error) {
        // Handle any errors
      });
    }

Please note that in order to use this function, you must opt-in to version 2 of Security Rules, which can be done by making rules_version = '2'; the first line of your security rules:

    rules_version = '2';
    service firebase.storage {
      match /b/{bucket}/o {
        match /{allPaths=**} {

I'd recommend checking the docs for further reference.

Also, according to setup, on Step 5, this script is not allowed for Node.js since require("firebase/app"); won't return firebase.storage() as a function. This is only achieved using import * as firebase from 'firebase/app';.

Since Firebase SDKs for JavaScript release 6.1, iOS release 6.4, and Android release version 18.1 all have a method to list files.

The documentation is a bit sparse so far, so I recommend checking out Rosário's answer for details.

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Previous answer, since this approach can still be useful at times:

There currently is no API call in the Firebase SDK to list all files in a Cloud Storage folder from within an app. If you need such functionality, you should store the metadata of the files (such as the download URLs) in a place where you can list them. The Firebase Realtime Database and Cloud Firestore are perfect for this and allows you to also easily share the URLs with others.

You can find a good (but somewhat involved) sample of this in our FriendlyPix sample app. The relevant code for the web version is here, but there are also versions for iOS and Android.