How do I create a release key hash?

Creating a release key hash is an important step when setting up your Android app for release. The release key hash allows your app to authenticate itself with services like Google Play Licensing. Without a valid release key hash, your app will fail to properly integrate with these services. Don’t worry though, generating a release key hash is straightforward if you follow these steps.

What is a Release Key Hash?

A release key hash is a unique identifier that is generated from your app’s signed release keystore. It looks something like this:

12:34:56:78:90:…AB:CD:EF

This hash is used to confirm the authenticity of your app when connecting to services like Google Play Licensing. When your app attempts to access the Licensing service, it will pass the release key hash which is then checked against the hash Google has on record for your app.

If the hashes match, the Licensing service knows the request comes from your legitimate app rather than an impersonator. This prevents pirates and hackers from accessing services intended only for your authentic app.

Why Do You Need a Release Key Hash?

There are a few reasons why you need a valid release key hash for your Android app:

To enable Google Play Licensing – This allows your app to verify licensing status and avoid piracy.
For signing up for Google services – Services like Maps, Drive, and Firebase require the release hash to confirm your identity.
For release on app stores – The key hash provides your app a unique identity on release platforms like Google Play.

For security best practices – Using the release hash rather than the debug hash improves security for production apps.

Without a release key hash, your app may be unable to properly implement security measures or integrate with essential services. So it’s very important to generate this hash before releasing your app.

How to Generate a Release Key Hash

There are a couple ways to generate a release key hash for your Android app. The most common approach is to use keytool from the Java JDK. Here are the detailed steps:

Open a command prompt or terminal and navigate to your JDK bin directory. For example:

cd C:\Program Files\Java\jdk1.8.0_251\bin

Execute the keytool command. Specify your keystore path, alias and password. For example:

keytool -list -v -keystore c:\users\myuser\myapp.keystore -alias myapp -storepass mystorepass

In the output, look for the SHA1 hash beside the “SHA1:” field. Copy this hash excluding the colons. For example if you see:

SHA1: 12:34:56:78:90:...AB:CD:EF

You would copy “1234567890ABCDEF” as your release key hash.

And that’s it! You now have your app’s release key hash properly generated. This exact value should be provided when setting up services like Google Play Licensing.

Generating Hash on Windows

The above steps use keytool on Windows. Here are some notes for Windows users:

Open the command prompt as administrator
Navigate to your JDK bin folder. Usually C:\Program Files\Java\jdkXXXX\bin
Use the full keystore path like C:\Users\MyUser\myapp.keystore

Generating Hash on Mac/Linux

For Mac or Linux, the process is similar but using terminal instead of command prompt:

Open a terminal window
Navigate to your JDK bin folder. For example: cd /usr/lib/jvm/jdk1.8.0_251/bin

Run the keytool command with paths adjusted for your OS. For example:

  
keytool -list -v -keystore /users/myuser/myapp.keystore -alias myapp -storepass mystorepass

Copy the SHA1 hash as your release key hash

Using Gradle to Generate Hash

You can also use your Android app’s Gradle build script to generate the release hash. Add the following task:

task printHash {
    doLast {
        def stdout = new ByteArrayOutputStream()
        exec {
            commandLine 'keytool', '-list', '-v', '-keystore', 'myapp.keystore', '-alias', 'myapp', '-storepass', 'mystorepass'
            standardOutput = stdout
        }
        println stdout.toString()
    }
}

Then run gradle printHash from your app folder. The hash will be printed out.

Using Android Studio to Generate Hash

The latest versions of Android Studio can generate the release key hash for you:

Click Build > Generate Signed Bundle / APK

Fill in your keystore details like alias and password
Click the Release tab
Near the bottom, click Show dialog

A dialog will appear with your release key hash!

Storing the Release Hash Securely

Your release key hash is sensitive since it can be used to impersonate your app. So you should take care not to expose the raw value publicly. A few tips:

Do not commit the raw hash value to source control

Store the value in a credentials file or environment variable instead of code
Only provide the hash when required during app setup flows

With proper security practices, your release key hash will remain safe and usable across all your app’s integrations.

Using the Hash for Google Play Services

One of the most common uses for the release hash is when setting up Google services for your app, such as:

Google Maps
Firebase

Google Drive
Google Play Licensing

For example, when setting up Google Play Licensing, you will register your app’s package name and release key hash in the Google Play Console. Google will use the hash to verify your app when it connects to Google’s Licensing service.

The release hash is also needed when adding various Firebase services to your app. The hash helps Firebase confirm your app’s identity across its many backend services.

So whenever you are prompted for a release hash during Google Play or Firebase setup, you should provide the value generated using the steps above.

Using the Hash for Other Services

Any service that needs to authenticate your Android app is a candidate for using your release key hash. Aside from Google, other examples include:

Facebook SDK
Twitter SDK
Paid APIs like movie listings

Real-time gaming services
Privileged enterprise services
Device-specific licensing like HD codecs

Most third party SDKs and APIs will walk you through how to integrate the release hash during their setup process. Just follow their documentation and provide your hash when needed.

Hash Instead of Keystore for Security

You might wonder why services ask for your key hash instead of the actual keystore file. There are a few security benefits to using the hash:

The hash acts like a fingerprint rather than full credentials

A breach of the hash alone does not compromise signing ability
The hash can be regenerated if needed without changing keys
The same hash verifies across multiple distributed services

By asking for your release key hash, these services can authenticate your app without seeing your highly sensitive keystore. So you retain control over the full signing credentials.

What if My Hash Changes?

In some cases, you may need to update your app’s release key hash from what was originally registered. Reasons this could happen:

You lost the original keystore and had to generate a new one

You are migrating or renaming keystores
You accidentally registered the debug key hash instead of release

When this happens, you will have to re-register the new release hash value with all integrated services. For example in Google Play, you can now associate multiple release key hashes with your app.

Any service using your hash will likely have a way to update the registered value. Just follow their instructions to provide a new hash when required.

Conclusion

Generating and integrating your Android app’s release key hash is essential for security, licensing, and service integrity. By following the steps in this guide, you can properly generate a hash using keytool, Gradle, or Android Studio.

Be sure to keep the value secure and provide it only when required by services like Google Play. If you ever need to update the hash, most providers have a way to re-register the new value.

With your release key hash in place, your app will be uniquely identified and verified across all integrated services. This allows them to confirm your app’s authenticity and provide access to privileged features.