diff --git a/frontend/src/components/PacketVisualizer3D.tsx b/frontend/src/components/PacketVisualizer3D.tsx
index 6022231..c22c1c5 100644
--- a/frontend/src/components/PacketVisualizer3D.tsx
+++ b/frontend/src/components/PacketVisualizer3D.tsx
@@ -25,6 +25,7 @@ import {
   type ContactAdvertPathSummary,
 } from '../types';
 import { getRawPacketObservationKey } from '../utils/rawPacketIdentity';
+import { getVisualizerSettings, saveVisualizerSettings } from '../utils/visualizerSettings';
 import { Checkbox } from './ui/checkbox';
 import {
   type NodeType,
@@ -34,7 +35,6 @@ import {
   COLORS,
   PARTICLE_COLOR_MAP,
   PARTICLE_SPEED,
-  DEFAULT_OBSERVATION_WINDOW_SEC,
   PACKET_LEGEND_ITEMS,
   parsePacket,
   getPacketLabel,
@@ -1007,19 +1007,55 @@ export function PacketVisualizer3D({
   const mouseRef = useRef(new THREE.Vector2());
 
   // Options
-  const [showAmbiguousPaths, setShowAmbiguousPaths] = useState(true);
-  const [showAmbiguousNodes, setShowAmbiguousNodes] = useState(false);
-  const [useAdvertPathHints, setUseAdvertPathHints] = useState(true);
-  const [splitAmbiguousByTraffic, setSplitAmbiguousByTraffic] = useState(true);
-  const [chargeStrength, setChargeStrength] = useState(-200);
-  const [observationWindowSec, setObservationWindowSec] = useState(DEFAULT_OBSERVATION_WINDOW_SEC);
-  const [letEmDrift, setLetEmDrift] = useState(true);
-  const [particleSpeedMultiplier, setParticleSpeedMultiplier] = useState(2);
-  const [showControls, setShowControls] = useState(true);
-  const [autoOrbit, setAutoOrbit] = useState(false);
-  const [pruneStaleNodes, setPruneStaleNodes] = useState(false);
+  const [savedSettings] = useState(getVisualizerSettings);
+  const [showAmbiguousPaths, setShowAmbiguousPaths] = useState(savedSettings.showAmbiguousPaths);
+  const [showAmbiguousNodes, setShowAmbiguousNodes] = useState(savedSettings.showAmbiguousNodes);
+  const [useAdvertPathHints, setUseAdvertPathHints] = useState(savedSettings.useAdvertPathHints);
+  const [splitAmbiguousByTraffic, setSplitAmbiguousByTraffic] = useState(
+    savedSettings.splitAmbiguousByTraffic
+  );
+  const [chargeStrength, setChargeStrength] = useState(savedSettings.chargeStrength);
+  const [observationWindowSec, setObservationWindowSec] = useState(
+    savedSettings.observationWindowSec
+  );
+  const [letEmDrift, setLetEmDrift] = useState(savedSettings.letEmDrift);
+  const [particleSpeedMultiplier, setParticleSpeedMultiplier] = useState(
+    savedSettings.particleSpeedMultiplier
+  );
+  const [showControls, setShowControls] = useState(savedSettings.showControls);
+  const [autoOrbit, setAutoOrbit] = useState(savedSettings.autoOrbit);
+  const [pruneStaleNodes, setPruneStaleNodes] = useState(savedSettings.pruneStaleNodes);
   const [repeaterAdvertPaths, setRepeaterAdvertPaths] = useState<ContactAdvertPathSummary[]>([]);
 
+  // Persist visualizer controls to localStorage on change
+  useEffect(() => {
+    saveVisualizerSettings({
+      showAmbiguousPaths,
+      showAmbiguousNodes,
+      useAdvertPathHints,
+      splitAmbiguousByTraffic,
+      chargeStrength,
+      observationWindowSec,
+      letEmDrift,
+      particleSpeedMultiplier,
+      pruneStaleNodes,
+      autoOrbit,
+      showControls,
+    });
+  }, [
+    showAmbiguousPaths,
+    showAmbiguousNodes,
+    useAdvertPathHints,
+    splitAmbiguousByTraffic,
+    chargeStrength,
+    observationWindowSec,
+    letEmDrift,
+    particleSpeedMultiplier,
+    pruneStaleNodes,
+    autoOrbit,
+    showControls,
+  ]);
+
   useEffect(() => {
     let cancelled = false;
 
diff --git a/frontend/src/utils/visualizerSettings.ts b/frontend/src/utils/visualizerSettings.ts
new file mode 100644
index 0000000..82b17ab
--- /dev/null
+++ b/frontend/src/utils/visualizerSettings.ts
@@ -0,0 +1,89 @@
+const VISUALIZER_SETTINGS_KEY = 'remoteterm-visualizer-settings';
+
+export interface VisualizerSettings {
+  showAmbiguousPaths: boolean;
+  showAmbiguousNodes: boolean;
+  useAdvertPathHints: boolean;
+  splitAmbiguousByTraffic: boolean;
+  chargeStrength: number;
+  observationWindowSec: number;
+  letEmDrift: boolean;
+  particleSpeedMultiplier: number;
+  pruneStaleNodes: boolean;
+  autoOrbit: boolean;
+  showControls: boolean;
+}
+
+export const VISUALIZER_DEFAULTS: VisualizerSettings = {
+  showAmbiguousPaths: true,
+  showAmbiguousNodes: false,
+  useAdvertPathHints: true,
+  splitAmbiguousByTraffic: true,
+  chargeStrength: -200,
+  observationWindowSec: 15,
+  letEmDrift: true,
+  particleSpeedMultiplier: 2,
+  pruneStaleNodes: false,
+  autoOrbit: false,
+  showControls: true,
+};
+
+export function getVisualizerSettings(): VisualizerSettings {
+  try {
+    const raw = localStorage.getItem(VISUALIZER_SETTINGS_KEY);
+    if (!raw) return { ...VISUALIZER_DEFAULTS };
+    const parsed = JSON.parse(raw) as Partial<VisualizerSettings>;
+    return {
+      showAmbiguousPaths:
+        typeof parsed.showAmbiguousPaths === 'boolean'
+          ? parsed.showAmbiguousPaths
+          : VISUALIZER_DEFAULTS.showAmbiguousPaths,
+      showAmbiguousNodes:
+        typeof parsed.showAmbiguousNodes === 'boolean'
+          ? parsed.showAmbiguousNodes
+          : VISUALIZER_DEFAULTS.showAmbiguousNodes,
+      useAdvertPathHints:
+        typeof parsed.useAdvertPathHints === 'boolean'
+          ? parsed.useAdvertPathHints
+          : VISUALIZER_DEFAULTS.useAdvertPathHints,
+      splitAmbiguousByTraffic:
+        typeof parsed.splitAmbiguousByTraffic === 'boolean'
+          ? parsed.splitAmbiguousByTraffic
+          : VISUALIZER_DEFAULTS.splitAmbiguousByTraffic,
+      chargeStrength:
+        typeof parsed.chargeStrength === 'number'
+          ? parsed.chargeStrength
+          : VISUALIZER_DEFAULTS.chargeStrength,
+      observationWindowSec:
+        typeof parsed.observationWindowSec === 'number'
+          ? parsed.observationWindowSec
+          : VISUALIZER_DEFAULTS.observationWindowSec,
+      letEmDrift:
+        typeof parsed.letEmDrift === 'boolean' ? parsed.letEmDrift : VISUALIZER_DEFAULTS.letEmDrift,
+      particleSpeedMultiplier:
+        typeof parsed.particleSpeedMultiplier === 'number'
+          ? parsed.particleSpeedMultiplier
+          : VISUALIZER_DEFAULTS.particleSpeedMultiplier,
+      pruneStaleNodes:
+        typeof parsed.pruneStaleNodes === 'boolean'
+          ? parsed.pruneStaleNodes
+          : VISUALIZER_DEFAULTS.pruneStaleNodes,
+      autoOrbit:
+        typeof parsed.autoOrbit === 'boolean' ? parsed.autoOrbit : VISUALIZER_DEFAULTS.autoOrbit,
+      showControls:
+        typeof parsed.showControls === 'boolean'
+          ? parsed.showControls
+          : VISUALIZER_DEFAULTS.showControls,
+    };
+  } catch {
+    return { ...VISUALIZER_DEFAULTS };
+  }
+}
+
+export function saveVisualizerSettings(settings: VisualizerSettings): void {
+  try {
+    localStorage.setItem(VISUALIZER_SETTINGS_KEY, JSON.stringify(settings));
+  } catch {
+    // localStorage may be unavailable
+  }
+}