diff --git a/native-messaging/app/ping_pong.py b/native-messaging/app/ping_pong.py
index c987f60..e934380 100755
--- a/native-messaging/app/ping_pong.py
+++ b/native-messaging/app/ping_pong.py
@@ -18,7 +18,12 @@ try:
     # Encode a message for transmission,
     # given its content.
     def encodeMessage(messageContent):
-        encodedContent = json.dumps(messageContent).encode('utf-8')
+        # https://docs.python.org/3/library/json.html#basic-usage
+        # To get the most compact JSON representation, you should specify 
+        # (',', ':') to eliminate whitespace.
+        # We want the most compact representation because the browser rejects
+        # messages that exceed 1 MB.
+        encodedContent = json.dumps(messageContent, separators=(',', ':')).encode('utf-8')
         encodedLength = struct.pack('@I', len(encodedContent))
         return {'length': encodedLength, 'content': encodedContent}
 
@@ -46,7 +51,12 @@ except AttributeError:
     # Encode a message for transmission,
     # given its content.
     def encodeMessage(messageContent):
-        encodedContent = json.dumps(messageContent)
+        # https://docs.python.org/3/library/json.html#basic-usage
+        # To get the most compact JSON representation, you should specify 
+        # (',', ':') to eliminate whitespace.
+        # We want the most compact representation because the browser rejects
+        # messages that exceed 1 MB.
+        encodedContent = json.dumps(messageContent, separators=(',', ':'))
         encodedLength = struct.pack('@I', len(encodedContent))
         return {'length': encodedLength, 'content': encodedContent}