diff --git a/webapp/path_navigator.html b/webapp/path_navigator.html
index d069dfd..373bd16 100644
--- a/webapp/path_navigator.html
+++ b/webapp/path_navigator.html
@@ -283,6 +283,7 @@
             <input type="number" id="fundamentalInput" value="110" style="width: 60px;">
             <span style="margin-left: 15px;">Octave:</span>
             <input type="number" id="octaveInput" value="2" style="width: 40px;">
+            <button id="toggleUnitBtn" style="margin-left: 15px;">Show: Cents</button>
         </div>
         
         <div class="controls">
@@ -317,6 +318,53 @@
         let hasPrev = false;
         let hasNext = false;
         let allGraphsData = null;
+        let displayMode = 'cents';
+        
+        // Parse fraction string like "3/2" or "1" into a number
+        function parseFraction(fracStr) {
+            if (!fracStr || fracStr === "1") return 1;
+            const parts = fracStr.split('/');
+            if (parts.length === 2) {
+                return parseInt(parts[0]) / parseInt(parts[1]);
+            }
+            return parseFloat(fracStr);
+        }
+        
+        // Toggle between cents and frequency display
+        function toggleDisplayUnit() {
+            displayMode = displayMode === 'cents' ? 'frequency' : 'cents';
+            const btn = document.getElementById('toggleUnitBtn');
+            if (btn) {
+                btn.textContent = displayMode === 'cents' ? 'Show: Cents' : 'Show: Frequency';
+            }
+            
+            if (!cy) return;
+            
+            const fundamental = parseFloat(document.getElementById("fundamentalInput").value) || 110;
+            
+            cy.nodes().forEach(node => {
+                const cents = node.data('cents');
+                const fraction = node.data('fraction');
+                
+                if (displayMode === 'frequency' && fraction) {
+                    const frac = parseFraction(fraction);
+                    const freq = fundamental * frac;
+                    node.data('displayLabel', Math.round(freq * 10) / 10);
+                } else {
+                    node.data('displayLabel', cents);
+                }
+                
+                node.style('label', node.data('displayLabel'));
+            });
+        }
+        
+        // Set up toggle button listener after DOM loads
+        document.addEventListener('DOMContentLoaded', () => {
+            const toggleBtn = document.getElementById('toggleUnitBtn');
+            if (toggleBtn) {
+                toggleBtn.addEventListener('click', toggleDisplayUnit);
+            }
+        });
         
         // Cytoscape instance
         let cy = null;
@@ -343,7 +391,7 @@
                             'background-color': 'data(color)',
                             'width': 32,
                             'height': 32,
-                            'label': 'data(cents)',
+                            'label': function(ele) { return ele.data('displayLabel'); },
                             'text-valign': 'center',
                             'text-halign': 'center',
                             'color': '#000000',
@@ -572,6 +620,8 @@
                             id: nodeId,
                             localId: n.id,
                             cents: n.cents,
+                            displayLabel: n.cents,
+                            fraction: n.fraction || "1",
                             chordIndex: chordIdx,
                             chordLabel: `c${chordIdx}`,
                             color: voiceColors[n.id % voiceColors.length],
@@ -724,6 +774,7 @@
                 nodes.push({
                     id: i,
                     cents: Math.round(cents),
+                    displayLabel: Math.round(cents),
                     fraction: pitch.fraction || "1",
                     hs_array: pitch.hs_array || []
                 });
@@ -1020,6 +1071,8 @@
                 }).catch(err => {
                     console.log('Error sending kill:', err);
                 });
+            } else if (e.key === "f" || e.key === "F") {
+                toggleDisplayUnit();
             }
         });