diff --git a/zebra-report/index.html b/zebra-report/index.html
index 29632a1..d069bba 100644
--- a/zebra-report/index.html
+++ b/zebra-report/index.html
@@ -1010,7 +1010,8 @@ function renderOutbox() {
 function scheduleRetransmit(crc) {
   const entry = msgPending.get(crc);
   if (!entry) return;
-  const wait = estimateTxMs(entry.frame.length) + estimateTxMs(15) + 4000;  /* data + ack + margin */
+  const base = estimateTxMs(entry.frame.length) + estimateTxMs(15) + 4000;  /* data + ack + margin */
+  const wait = base * Math.pow(1.8, entry.tries - 1);   /* exponential backoff — don't hammer */
   entry.timer = setTimeout(async () => {
     const e = msgPending.get(crc);
     if (!e) return;                       /* already ACKed */