Skip to main content

Setting up Your Flutter Release Signing Key

Image of Daniel Reynolds
Daniel Reynolds
Software Engineer
GitHubLinkedIn
Read More
Full stack engineer with nearly a decade of experience developing various applications and software

Last updated: July 2025

You've just polished up your build, ran flutter build appbundle, and you're ready to publish your build to the internal testing track. But you're greeted by the following error after uploading your first build:

You uploaded an APK or Android App Bundle that was signed in debug mode. You need to sign your APK or Android App Bundle in release mode.

Sound familiar? This guide is for you.

Background​

I ran into this while setting up my first release for my caffeine-quitting app "Decaf" - these are the steps I took to solve it. I hope this guide helps you out!

Creating an Upload Keystore​

Check out Flutter's Official Guide for this, it is perfect! Link Here

Once you are done, you will have

  1. Generated a Keystore
  2. Created a key.properties file
  3. Updated your build.gradle file

And that is it! I hope this guide pointed you in the right direction. You should be able to upload your build to the Play Store with no errors.