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QML Hot Reload with Felgo Live

The easiest cross-platform hot reloading, for Qt and Felgo.


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Focus on Development

Stop Waiting for Build, Package and Deployment Steps

Hot Reload with Felgo Live allows you to change your QML & JavaScript source code and view the result in realtime. It applies QML, JavaScript and asset changes instantly on every connected device, immediately after saving. This reduces the long waiting times for build and deployment steps to only a couple of seconds.

QML Hot Reload with Felgo Live can be used to review and test code changes inside the running application, on Mobile, Desktop, Embedded and Web platforms.


Hot Reload applies changes in your source code without losing the state of your application. If you are currently working on a sub-page, you will not have to navigate back to it after every change, you will stay exactly where you are in your app.


Save Time 

Deploy and Test in Seconds

Felgo Live reduces deployment time, from several minutes to a couple of seconds. It deploys your code changes to all connected devices, automatically after saving. Save more than 95% of time on deployment for testing!

Incremental UI Building 

Define Interaction Seamlessly

You can build your user interface incrementally while navigating it at the same time, and iterate on any sub-page without navigating to it repeatedly.Work on a single screen until it is pixel perfect, without ever leaving it.

Hot Reload also allows you to add any form of interaction to the running QML application, like property bindings, signal handlers or any other JavaScript.


Concurrent Testing 

on All Your Devices

You can connect as many devices as you want, and every single one is updated simultaneously. This allows you to test any change on different platforms and devices at the same time.

Review and test your code changes in realtime on Mobile, Desktop, Embedded and Web platforms in just seconds.

iOS Deployment from Windows & Linux

With Felgo Live, you can test your Felgo projects on your iPhone and iPad, even from Windows or Linux. No more need to ask your office neighbor with that shiny Mac, to build your application for iOS.

No Native SDKs Required

You don’t need to install native mobile SDK for Android or iOS to develop and test your apps on mobile phones.


Felgo Plugins 

without Additional Setup

Test Felgo Plugins like Admob Ads, Facebook Login, Google Analytics, Firebase or push notifications. With Felgo Live you can skip the individual setup steps.


1. Start Felgo Live

You can start Felgo Live for your active project, by clicking on the LIVE-Run button in Qt Creator.

This will open the Felgo Live Server and a desktop Live Client for local testing. The desktop client will automatically connect to the server.


2. Connect Live Clients

If you want to connect your mobile devices, download and start the Felgo Live App for Android or iOS.

Select Connect Desktop in the app and accept the connection request in the Live Server. Felgo Live is using your local network, please make sure that all your devices are connected to the same local network.

3. That's it!

Once you have connected a Live Client, your project is automatically loaded in your Live Client. Every change to your source code will now be shown in real-time on any connected Live Client, as soon as you save your file.

C++ & Native Code 

Build your own Live Clients

Some projects include custom C++ or native code. Those languages require a compilation step and cannot be reloaded directly with QML live reloading.

You can build your own Live Clients that include all your custom code with just 3 additional lines of code, using the Live Client Module.

Test this example on your mobile phone now! Run This Example
 import Felgo 3.0
 import QtQuick 2.8

 App {

   NavigationStack {
     Page {
       title: "My First App"

       AppButton {
anchors.centerIn: parent text: "Celebrate" onClicked: { nativeUtils.displayAlertDialog("Yay", "That is so cool!") } } } } }

Cloud IDE

Hot Reloading right from your Browser

With the Felgo Web Editor, you can test QML code from your Browser on your iOS and Android devices.

Test Code Examples

You can test code examples from the documentation directly on your phone, with QML live reloading.

Share Code Snippets

You can save and share code snippets, to show them to other developers or customers.