diff --git a/React/Base/RCTBridge.h b/React/Base/RCTBridge.h
index 51b2ec0cb..889c4b3e5 100644
--- a/React/Base/RCTBridge.h
+++ b/React/Base/RCTBridge.h
@@ -44,6 +44,24 @@ RCT_EXTERN NSString *const RCTJavaScriptDidFailToLoadNotification;
  */
 RCT_EXTERN NSString *const RCTDidInitializeModuleNotification;
 
+/**
+ * This notification fires just before the bridge starts processing a request to
+ * reload.
+ */
+RCT_EXTERN NSString *const RCTBridgeWillReloadNotification;
+
+/**
+ * This notification fires just before the bridge begins downloading a script
+ * from the packager.
+ */
+RCT_EXTERN NSString *const RCTBridgeWillDownloadScriptNotification;
+
+/**
+ * This notification fires just after the bridge finishes downloading a script
+ * from the packager.
+ */
+RCT_EXTERN NSString *const RCTBridgeDidDownloadScriptNotification;
+
 /**
  * This block can be used to instantiate modules that require additional
  * init parameters, or additional configuration prior to being used.
diff --git a/React/Base/RCTBridge.m b/React/Base/RCTBridge.m
index c769a3664..85ee29802 100644
--- a/React/Base/RCTBridge.m
+++ b/React/Base/RCTBridge.m
@@ -29,6 +29,9 @@ NSString *const RCTJavaScriptWillStartLoadingNotification = @"RCTJavaScriptWillS
 NSString *const RCTJavaScriptDidLoadNotification = @"RCTJavaScriptDidLoadNotification";
 NSString *const RCTJavaScriptDidFailToLoadNotification = @"RCTJavaScriptDidFailToLoadNotification";
 NSString *const RCTDidInitializeModuleNotification = @"RCTDidInitializeModuleNotification";
+NSString *const RCTBridgeWillReloadNotification = @"RCTBridgeWillReloadNotification";
+NSString *const RCTBridgeWillDownloadScriptNotification = @"RCTBridgeWillDownloadScriptNotification";
+NSString *const RCTBridgeDidDownloadScriptNotification = @"RCTBridgeDidDownloadScriptNotification";
 
 static NSMutableArray<Class> *RCTModuleClasses;
 NSArray<Class> *RCTGetModuleClasses(void)
@@ -260,6 +263,8 @@ RCT_NOT_IMPLEMENTED(- (instancetype)init)
   [RCTInspectorDevServerHelper disableDebugger];
   #endif
 
+  [[NSNotificationCenter defaultCenter] postNotificationName:RCTBridgeWillReloadNotification object:self];
+
   /**
    * Any thread
    */
diff --git a/React/CxxBridge/RCTCxxBridge.mm b/React/CxxBridge/RCTCxxBridge.mm
index 9d24ebb31..fd0346a74 100644
--- a/React/CxxBridge/RCTCxxBridge.mm
+++ b/React/CxxBridge/RCTCxxBridge.mm
@@ -377,6 +377,8 @@ struct RCTInstanceCallback : public InstanceCallback {
 
 - (void)loadSource:(RCTSourceLoadBlock)_onSourceLoad onProgress:(RCTSourceLoadProgressBlock)onProgress
 {
+  NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
+  [center postNotificationName:RCTBridgeWillDownloadScriptNotification object:_parentBridge];
   [_performanceLogger markStartForTag:RCTPLScriptDownload];
   NSUInteger cookie = RCTProfileBeginAsyncEvent(0, @"JavaScript download", nil);
 
@@ -388,6 +390,8 @@ struct RCTInstanceCallback : public InstanceCallback {
     RCTProfileEndAsyncEvent(0, @"native", cookie, @"JavaScript download", @"JS async");
     [performanceLogger markStopForTag:RCTPLScriptDownload];
     [performanceLogger setValue:sourceLength forTag:RCTPLBundleSize];
+    [center postNotificationName:RCTBridgeDidDownloadScriptNotification object:self->_parentBridge];
+
     _onSourceLoad(error, source, sourceLength);
   };