Android Studio Gradle Sync: Unknown Host d29vzk4ow07wi7.cloudfront.net
Gradle sync fails because a Maven repo URL is blocked or unreachable. The fix is usually a proxy config or switching to HTTPS.
You’re not alone — this error is a classic pain point
I know it’s infuriating when Android Studio just sits there spinning, then throws Unknown host 'd29vzk4ow07wi7.cloudfront.net'. This tripped me up the first time too, especially after a network change. Let’s get it fixed.
The immediate fix: switch to HTTPS or configure your proxy
The host d29vzk4ow07wi7.cloudfront.net is a CloudFront CDN serving Maven artifacts (often used by Facebook React Native or Mapbox dependencies). If you’re behind a corporate firewall or a strict ISP, HTTP requests to it can get blocked while HTTPS passes through.
Option 1: Force HTTPS in your project-level build.gradle
Open your project’s build.gradle (the one at the root, not app-level). Look for any maven { url "http://..." } blocks. Change them to HTTPS:
// Before (blocked)
maven { url "http://d29vzk4ow07wi7.cloudfront.net" }
// After (works)
maven { url "https://d29vzk4ow07wi7.cloudfront.net" }
If you don’t see that URL directly, it might be inside a plugin (like com.facebook.react for React Native). In that case, go to File > Settings > Build, Execution, Deployment > Build Tools > Gradle and check Offline work. This forces Gradle to use cached dependencies — not a long-term fix, but it gets you unblocked immediately.
Option 2: Configure your proxy in gradle.properties
If you’re on a corporate network, Gradle might not be picking up your system proxy. Add these lines to ~/.gradle/gradle.properties (or gradle.properties in your project):
systemProp.http.proxyHost=your-proxy-host
systemProp.http.proxyPort=8080
systemProp.https.proxyHost=your-proxy-host
systemProp.https.proxyPort=8080
Replace with your actual proxy host/port. If you need authentication, add:
systemProp.http.proxyUser=username
systemProp.http.proxyPassword=password
Option 3: Clear Gradle cache and retry
Sometimes the cache gets corrupted with partial downloads. Blow it away:
cd ~/.gradle
rm -rf caches
Then do File > Invalidate Caches and Restart in Android Studio. This forces a fresh download — but only helps if the network issue is fixed first.
Why this error happens
The domain d29vzk4ow07wi7.cloudfront.net is a CloudFront distribution. CloudFront’s IP ranges change often. Your corporate firewall might be blocking an IP range, or your ISP’s DNS is failing to resolve it. Gradle falls flat because it can’t even connect to the host. The HTTP vs HTTPS thing is also common — some proxies only allow HTTPS outbound, so HTTP requests get dropped silently.
Less common variations
I’ve seen this error pop up with other CloudFront hosts too — d1m5q1a42c7nbt.cloudfront.net, d2r1vj7n5y8m4.cloudfront.net. They’re all the same pattern: a Maven repository behind CloudFront. The fix is identical. If you’re stuck, run nslookup d29vzk4ow07wi7.cloudfront.net — if it fails, your DNS is the culprit. Switch to Google DNS (8.8.8.8) or Cloudflare DNS (1.1.1.1) in your network settings.
Another variation: the error shows up only on Windows but not macOS, because Windows Defender or a third-party antivirus is intercepting the connection. Temporarily disable it, sync, then re-enable.
Prevention: lock your dependencies and use a mirror
To keep this from biting you again:
- Use a Maven mirror in your
build.gradle. Many organizations host a local Nexus or Artifactory that caches external repos. Change your repository block to point there instead of the raw CloudFront URL. - Pin dependency versions in
build.gradle— avoid dynamic versions like+orlatest.release. They trigger fresh checks every sync, making failures more likely. - Enable Gradle offline mode when you’re on an unstable network — it’s a checkbox in the Gradle tool window (elephant icon). This prevents any network calls during sync.
- Keep Android Studio and Gradle updated — newer versions handle proxy and SSL issues better. I’ve seen Studio 4.2+ fail less often with these CDN errors than Studio 3.x.
One last thing
If none of this works, check if the URL is actually valid. Open https://d29vzk4ow07wi7.cloudfront.net in a browser — if you get a 404 or timeout, the repo has moved or is down. In that case, find the official replacement URL from the dependency’s docs. I’ve wasted hours chasing a dead URL. Don’t be me.
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