diff --git a/lib/components/SchematicViewer.tsx b/lib/components/SchematicViewer.tsx
index 3697732..00c78e6 100644
--- a/lib/components/SchematicViewer.tsx
+++ b/lib/components/SchematicViewer.tsx
@@ -26,6 +26,7 @@ import { SpiceSimulationIcon } from "./SpiceSimulationIcon"
 import { SpiceSimulationOverlay } from "./SpiceSimulationOverlay"
 import { zIndexMap } from "../utils/z-index-map"
 import { useSpiceSimulation } from "../hooks/useSpiceSimulation"
+import { useHighlightConnectedTracesOnHover } from "../hooks/useHighlightConnectedTracesOnHover"
 import { getSpiceFromCircuitJson } from "../utils/spice-utils"
 import { getStoredBoolean, setStoredBoolean } from "lib/hooks/useLocalStorage"
 import { MouseTracker } from "./MouseTracker"
@@ -351,6 +352,12 @@ export const SchematicViewer = ({
     editEvents: editEventsWithUnappliedEditEvents,
   })
 
+  useHighlightConnectedTracesOnHover({
+    svgDivRef,
+    circuitJson,
+    circuitJsonKey,
+  })
+
   // Add group overlays when enabled
   useSchematicGroupsOverlay({
     svgDivRef,
diff --git a/lib/hooks/useHighlightConnectedTracesOnHover.ts b/lib/hooks/useHighlightConnectedTracesOnHover.ts
new file mode 100644
index 0000000..c275f22
--- /dev/null
+++ b/lib/hooks/useHighlightConnectedTracesOnHover.ts
@@ -0,0 +1,175 @@
+import { useEffect, useRef } from "react"
+import type { CircuitJson } from "circuit-json"
+
+/**
+ * Highlights all schematic traces on the same net when hovering any trace.
+ * Builds a traceId -> netId mapping from circuit JSON, then attaches
+ * mouseenter/mouseleave listeners to trace SVG elements.
+ */
+export const useHighlightConnectedTracesOnHover = ({
+  svgDivRef,
+  circuitJson,
+  circuitJsonKey,
+}: {
+  svgDivRef: React.RefObject<HTMLDivElement | null>
+  circuitJson: CircuitJson
+  circuitJsonKey: string
+}) => {
+  const cleanupRef = useRef<(() => void) | null>(null)
+
+  useEffect(() => {
+    const svg = svgDivRef.current
+    if (!svg) return
+
+    // Cleanup previous listeners
+    cleanupRef.current?.()
+
+    // Build traceId -> netId mapping
+    const traceToNetMap = new Map<string, string>()
+
+    try {
+      const sourceTraces = (circuitJson as any[]).filter(
+        (item) => item.type === "source_trace",
+      )
+
+      const schematicTraces = (circuitJson as any[]).filter(
+        (item) => item.type === "schematic_trace",
+      )
+
+      // Build source_trace_id -> net connectivity
+      // Two traces are on the same net if they share a connected source port
+      const portToTraces = new Map<string, Set<string>>()
+      const traceToPorts = new Map<string, Set<string>>()
+
+      for (const st of sourceTraces) {
+        const traceId = st.source_trace_id
+        const ports = (st.connected_source_port_ids ?? []) as string[]
+        traceToPorts.set(traceId, new Set(ports))
+        for (const port of ports) {
+          if (!portToTraces.has(port)) portToTraces.set(port, new Set())
+          portToTraces.get(port)!.add(traceId)
+        }
+      }
+
+      // Union-Find to group traces by net (connected through shared ports)
+      const parent = new Map<string, string>()
+      const find = (x: string): string => {
+        if (!parent.has(x)) parent.set(x, x)
+        if (parent.get(x) !== x) parent.set(x, find(parent.get(x)!))
+        return parent.get(x)!
+      }
+      const union = (a: string, b: string) => {
+        const ra = find(a)
+        const rb = find(b)
+        if (ra !== rb) parent.set(ra, rb)
+      }
+
+      for (const ports of traceToPorts.values()) {
+        const portArr = Array.from(ports)
+        for (let i = 1; i < portArr.length; i++) {
+          union(portArr[0], portArr[i])
+        }
+      }
+
+      // Assign net IDs (use the root of the union-find group)
+      for (const st of sourceTraces) {
+        const traceId = st.source_trace_id
+        const netId = find(traceId)
+        traceToNetMap.set(traceId, netId)
+      }
+
+      // Map schematic traces to nets
+      const schematicTraceToNet = new Map<string, string>()
+      for (const schTrace of schematicTraces) {
+        const srcTraceId = schTrace.source_trace_id
+        if (srcTraceId && traceToNetMap.has(srcTraceId)) {
+          schematicTraceToNet.set(
+            schTrace.schematic_trace_id,
+            traceToNetMap.get(srcTraceId)!,
+          )
+        }
+      }
+
+      if (schematicTraceToNet.size === 0) return
+
+      // Build netId -> set of schematic trace elements
+      const netToElements = new Map<string, Element[]>()
+      const allTraceElements = svg.querySelectorAll(
+        '[data-circuit-json-type="schematic_trace"]',
+      )
+
+      for (const el of Array.from(allTraceElements)) {
+        const traceId = el.getAttribute("data-schematic-trace-id")
+        if (!traceId) continue
+        const netId = schematicTraceToNet.get(traceId)
+        if (!netId) continue
+        if (!netToElements.has(netId)) netToElements.set(netId, [])
+        netToElements.get(netId)!.push(el)
+      }
+
+      // Add hover style
+      if (!svg.querySelector("style#trace-net-hover-style")) {
+        const style = document.createElement("style")
+        style.id = "trace-net-hover-style"
+        style.textContent = `
+          .trace-net-hovered path {
+            stroke: #f59e0b !important;
+            stroke-width: 3 !important;
+            filter: drop-shadow(0 0 4px rgba(245, 158, 11, 0.6)) !important;
+            transition: stroke 0.15s ease, stroke-width 0.15s ease, filter 0.15s ease;
+          }
+        `
+        svg.appendChild(style)
+      }
+
+      const handleEnter = (netId: string) => {
+        const elements = netToElements.get(netId)
+        if (!elements) return
+        for (const el of elements) {
+          el.classList.add("trace-net-hovered")
+        }
+      }
+
+      const handleLeave = (netId: string) => {
+        const elements = netToElements.get(netId)
+        if (!elements) return
+        for (const el of elements) {
+          el.classList.remove("trace-net-hovered")
+        }
+      }
+
+      // Attach listeners
+      const cleanups: (() => void)[] = []
+      for (const [traceId, netId] of schematicTraceToNet) {
+        const el = svg.querySelector(`[data-schematic-trace-id="${traceId}"]`)
+        if (!el) continue
+
+        const enterHandler = () => handleEnter(netId)
+        const leaveHandler = () => handleLeave(netId)
+
+        el.addEventListener("mouseenter", enterHandler)
+        el.addEventListener("mouseleave", leaveHandler)
+
+        // Make sure the element is hoverable
+        ;(el as HTMLElement).style.cursor = "pointer"
+
+        cleanups.push(() => {
+          el.removeEventListener("mouseenter", enterHandler)
+          el.removeEventListener("mouseleave", leaveHandler)
+        })
+      }
+
+      cleanupRef.current = () => {
+        for (const fn of cleanups) fn()
+        svg.querySelector("style#trace-net-hover-style")?.remove()
+      }
+    } catch (err) {
+      console.error("Failed to set up trace hover highlighting", err)
+    }
+
+    return () => {
+      cleanupRef.current?.()
+      cleanupRef.current = null
+    }
+  }, [svgDivRef, circuitJson, circuitJsonKey])
+}