AI & TechnologyJCenter Shutdown: Fixing Old Android and Flutter Builds

Bintray is gone and JCenter is now only a redirect to Maven Central, so an Android or Flutter project that still points at them can fail to build or fail to find some of its libraries. Often the fix is short: replace jcenter() with mavenCentral() and google(). The harder cases are old plugins that still declare JCenter and libraries that were never published anywhere else. Both are covered below.

If you landed here from an old Bintray link or a README that says to add JCenter, this is what changed and how to fix the build. The dates come from JFrog, Gradle and Android Developers, as listed in the sources. I tested the Bintray and JCenter addresses below myself on October 18, 2026.

Disclosure: App369 is my studio. I fix and maintain Flutter and Android apps for a living, and the last section mentions what I sell. No company named here paid for a mention.

What happened to Bintray and JCenter, and when

Android's JCenter migration page still says JCenter allows downloads of existing artifacts indefinitely. JFrog's 2024 post and Gradle's 9.0 upgrade guide both describe the redirect to Maven Central, and that redirect is what I saw when I tested it.

What the old addresses do today

Checked on October 18, 2026:

• bintray.com did not load: the connection timed out.
• dl.bintray.com, where many READMEs linked downloads and custom repositories, returned 404.
• jcenter.bintray.com returned a 301 redirect to repo1.maven.org, Maven Central.
• A library that was only ever published on JCenter, org.jetbrains.kotlinx:kotlinx-html-jvm:0.6.12, followed the redirect to Maven Central and returned 404.

So JCenter now works only for files that also exist on Maven Central. Anything else fails, sometimes with a confusing "could not find" error for a version you know used to exist.

How to fix the build

Work through these in order. In my experience, the first two fix many projects.

1. Replace jcenter() in your own build files. In an Android project, look in settings.gradle (or settings.gradle.kts) under pluginManagement and dependencyResolutionManagement, and in the top-level build.gradle under buildscript and allprojects. In a Flutter app the same files are under android/. Replace jcenter() with mavenCentral(), and make sure google() is there too. Keep gradlePluginPortal() in pluginManagement if it is already there.

   repositories {
       google()
       mavenCentral()
   }
   

2. Sync, then read the first error. If it names a library that can't be found, go to step 4. If it mentions jcenter() and points at a file you don't own, go to step 3.
3. Fix plugins and libraries that still declare JCenter. On Gradle 9 the build stops at any jcenter() call in a build file Gradle runs, and that includes Flutter plugins, which are built as part of your app. So in a Flutter app the culprit is usually an old plugin: check the plugin's changelog, then raise its version in pubspec.yaml and run flutter pub upgrade. If the plugin is unmaintained, look for a maintained fork or a replacement plugin. Editing files in the pub cache is fragile: the change doesn't reach CI or other machines, and it is lost when the cache is cleared or repaired. A fork referenced from dependency_overrides in pubspec.yaml is the safer way to patch a plugin. If you can't upgrade the plugin yet, staying on Gradle 8 buys time, but it doesn't fix the underlying problem.
4. Find a new home for JCenter-only libraries. Search Maven Central for the library. Many moved there under the same group ID, sometimes with a newer version only. If the source is on GitHub, JitPack can build it from a release tag: add maven { url 'https://jitpack.io' } and use com.github.<user>:<repo>:<tag> coordinates. JitPack builds the code itself, so check that the tag is the version you expect. As a last resort, put the JAR or AAR in a libs/ folder and depend on it as a local file. That works in the app module; in a plugin or library module, use a file-based Maven repository instead. A local file also drops the library's own dependencies, so add those yourself, and note the library as something to replace.
5. Check for other dead repositories. Remove any maven { url "https://dl.bintray.com/..." } lines. Each one is a dead address that slows down or breaks resolution.
6. Build from a clean state. Run the build with an empty Gradle cache (a fresh GRADLE_USER_HOME or a clean CI runner, plus flutter clean in a Flutter app) before you call it fixed. A cache on your own machine can hide a library that no longer downloads anywhere.

When it's more than a one-line change

A project that has sat untouched since 2020 or 2021 usually needs more than the repository change: newer Gradle and Android Gradle Plugin versions, a newer Kotlin, and a recent target API level, because Google Play requires updates to meet its current target API requirement (check the deadline in Play Console). Do those one at a time and build after each, so you know which change broke what.

For the iOS side of the same problem, see Flutter iOS build failed after an upgrade.

Need a hand?

If the build still fails after these steps, or the project is old enough that JCenter is only the first problem, the App Fix Ticket is two fixed-price steps. A $450 Diagnosis gives you the root cause with evidence and a fixed repair quote within 3 business days, credited toward the fix. If you go ahead, the $1,200 Fix takes 5 business days. If you're not sure it fits, send me a short description of the error and the project's age, and I'll tell you where I'd start.