diff --git a/public/index.html b/public/index.html
index 5d0ecc0..6e8bb59 100644
--- a/public/index.html
+++ b/public/index.html
@@ -83,7 +83,7 @@
   <script src="app.js?v=1774052279"></script>
   <script src="home.js?v=1774042199"></script>
   <script src="packets.js?v=1774052279"></script>
-  <script src="map.js?v=1774053337" onerror="console.error('Failed to load:', this.src)"></script>
+  <script src="map.js?v=1774053399" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="channels.js?v=1774050030" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="nodes.js?v=1774050030" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="traces.js?v=1774048777" onerror="console.error('Failed to load:', this.src)"></script>
diff --git a/public/map.js b/public/map.js
index 5c2c31c..19e1452 100644
--- a/public/map.js
+++ b/public/map.js
@@ -509,12 +509,17 @@
     const loc = (node.lat && node.lon) ? `${node.lat.toFixed(5)}, ${node.lon.toFixed(5)}` : '—';
     const lastAdvert = node.last_seen ? timeAgo(node.last_seen) : '—';
     const roleBadge = `<span style="display:inline-block;padding:2px 8px;border-radius:12px;font-size:11px;font-weight:600;background:${ROLE_COLORS[node.role] || '#4b5563'};color:#fff;">${(node.role || 'unknown').toUpperCase()}</span>`;
+    const hs = node.hash_size || 1;
+    const hashPrefix = node.public_key ? node.public_key.slice(0, hs * 2).toUpperCase() : '—';
+    const hashPrefixRow = `<dt style="color:var(--text-muted);float:left;clear:left;width:80px;padding:2px 0;">Hash Prefix</dt>
+          <dd style="font-family:var(--mono);font-size:11px;font-weight:700;margin-left:88px;padding:2px 0;">${safeEsc(hashPrefix)} <span style="font-weight:400;color:var(--text-muted);">(${hs}B)</span></dd>`;
 
     return `
       <div class="map-popup" style="font-family:var(--font);min-width:180px;">
         <h3 style="font-weight:700;font-size:14px;margin:0 0 4px;">${safeEsc(node.name || 'Unknown')}</h3>
         ${roleBadge}
         <dl style="margin-top:8px;font-size:12px;">
+          ${hashPrefixRow}
           <dt style="color:var(--text-muted);float:left;clear:left;width:80px;padding:2px 0;">Key</dt>
           <dd style="font-family:var(--mono);font-size:11px;margin-left:88px;padding:2px 0;">${safeEsc(key)}</dd>
           <dt style="color:var(--text-muted);float:left;clear:left;width:80px;padding:2px 0;">Location</dt>