diff --git a/public/index.html b/public/index.html
index 26f82a5..e46320d 100644
--- a/public/index.html
+++ b/public/index.html
@@ -842,6 +842,13 @@
 
                 <button onclick="refreshData()">[ 🔄 Refresh ]</button>
                 <button onclick="clearCompletedExecutions()" style="margin-left: 10px;">[ 🗑️ Clear Completed ]</button>
+                <button onclick="toggleCompareMode()" id="compareModeBtn" style="margin-left: 10px;">[ 📊 Compare Mode ]</button>
+                <button onclick="compareSelectedExecutions()" id="compareBtn" style="margin-left: 10px; display: none;">[ ⚖️ Compare Selected ]</button>
+
+                <div id="compareInstructions" style="display: none; background: rgba(255, 176, 0, 0.1); border: 2px solid var(--terminal-amber); padding: 12px; margin: 15px 0; color: var(--terminal-amber);">
+                    Select 2-5 executions to compare their outputs. Click executions to toggle selection.
+                </div>
+
                 <div id="executionList"><div class="loading">Loading...</div></div>
             </div>
         </div>
@@ -947,11 +954,22 @@
         </div>
     </div>
 
+    <!-- Compare Executions Modal -->
+    <div id="compareExecutionsModal" class="modal">
+        <div class="modal-content" style="max-width: 90%; max-height: 90vh;">
+            <h2>⚖️ Execution Comparison</h2>
+            <div id="compareContent" style="max-height: 70vh; overflow-y: auto; padding: 20px;"></div>
+            <button onclick="closeModal('compareExecutionsModal')">[ Close ]</button>
+        </div>
+    </div>
+
     <script>
         let currentUser = null;
         let ws = null;
         let workers = [];
         let allExecutions = []; // Store all loaded executions for filtering
+        let compareMode = false;
+        let selectedExecutions = [];
 
         async function loadUser() {
             try {
@@ -1195,16 +1213,23 @@
             // Render filtered results
             const fullHtml = filtered.length === 0 ?
                 '<div class="empty">No executions match your filters</div>' :
-                filtered.map(e => `
-                    <div class="execution-item" onclick="viewExecution('${e.id}')">
-                        <span class="status ${e.status}">${e.status}</span>
-                        <strong>${e.workflow_name || '[Quick Command]'}</strong>
-                        <div class="timestamp">
-                            Started by ${e.started_by} at ${new Date(e.started_at).toLocaleString()}
-                            ${e.completed_at ? ` • Completed at ${new Date(e.completed_at).toLocaleString()}` : ''}
+                filtered.map(e => {
+                    const isSelected = selectedExecutions.includes(e.id);
+                    const clickHandler = compareMode ? `toggleExecutionSelection('${e.id}')` : `viewExecution('${e.id}')`;
+                    const selectedStyle = isSelected ? 'background: rgba(255, 176, 0, 0.2); border-left-width: 5px; border-left-color: var(--terminal-amber);' : '';
+
+                    return `
+                        <div class="execution-item" onclick="${clickHandler}" style="${selectedStyle} cursor: pointer;">
+                            ${compareMode && isSelected ? '<span style="color: var(--terminal-amber); margin-right: 8px;">✓</span>' : ''}
+                            <span class="status ${e.status}">${e.status}</span>
+                            <strong>${e.workflow_name || '[Quick Command]'}</strong>
+                            <div class="timestamp">
+                                Started by ${e.started_by} at ${new Date(e.started_at).toLocaleString()}
+                                ${e.completed_at ? ` • Completed at ${new Date(e.completed_at).toLocaleString()}` : ''}
+                            </div>
                         </div>
-                    </div>
-                `).join('');
+                    `;
+                }).join('');
 
             document.getElementById('executionList').innerHTML = fullHtml;
         }
@@ -1219,6 +1244,211 @@
             renderFilteredExecutions();
         }
 
+        function toggleCompareMode() {
+            compareMode = !compareMode;
+            selectedExecutions = [];
+
+            const btn = document.getElementById('compareModeBtn');
+            const compareBtn = document.getElementById('compareBtn');
+            const instructions = document.getElementById('compareInstructions');
+
+            if (compareMode) {
+                btn.textContent = '[ ✗ Exit Compare Mode ]';
+                btn.style.borderColor = 'var(--terminal-amber)';
+                btn.style.color = 'var(--terminal-amber)';
+                compareBtn.style.display = 'inline-block';
+                instructions.style.display = 'block';
+            } else {
+                btn.textContent = '[ 📊 Compare Mode ]';
+                btn.style.borderColor = '';
+                btn.style.color = '';
+                compareBtn.style.display = 'none';
+                instructions.style.display = 'none';
+            }
+
+            renderFilteredExecutions();
+        }
+
+        function toggleExecutionSelection(executionId) {
+            const index = selectedExecutions.indexOf(executionId);
+
+            if (index > -1) {
+                selectedExecutions.splice(index, 1);
+            } else {
+                if (selectedExecutions.length >= 5) {
+                    showTerminalNotification('Maximum 5 executions can be compared', 'error');
+                    return;
+                }
+                selectedExecutions.push(executionId);
+            }
+
+            renderFilteredExecutions();
+
+            // Update compare button text
+            const compareBtn = document.getElementById('compareBtn');
+            if (selectedExecutions.length >= 2) {
+                compareBtn.textContent = `[ ⚖️ Compare Selected (${selectedExecutions.length}) ]`;
+            } else {
+                compareBtn.textContent = '[ ⚖️ Compare Selected ]';
+            }
+        }
+
+        async function compareSelectedExecutions() {
+            if (selectedExecutions.length < 2) {
+                showTerminalNotification('Please select at least 2 executions to compare', 'error');
+                return;
+            }
+
+            // Fetch detailed data for all selected executions
+            const executionDetails = [];
+            for (const execId of selectedExecutions) {
+                try {
+                    const response = await fetch(`/api/executions/${execId}`);
+                    if (response.ok) {
+                        executionDetails.push(await response.json());
+                    }
+                } catch (error) {
+                    console.error('Error fetching execution:', error);
+                }
+            }
+
+            if (executionDetails.length < 2) {
+                showTerminalNotification('Failed to load execution details', 'error');
+                return;
+            }
+
+            // Generate comparison view
+            let comparisonHtml = '<div style="display: grid; gap: 20px;">';
+
+            // Summary table
+            comparisonHtml += `
+                <div style="background: rgba(0, 255, 65, 0.05); border: 2px solid var(--terminal-green); padding: 15px;">
+                    <h3 style="margin-top: 0; color: var(--terminal-amber);">Comparison Summary</h3>
+                    <table style="width: 100%; border-collapse: collapse; font-family: var(--font-mono); font-size: 0.9em;">
+                        <thead>
+                            <tr style="border-bottom: 2px solid var(--terminal-green);">
+                                <th style="text-align: left; padding: 8px; color: var(--terminal-amber);">Execution</th>
+                                <th style="text-align: left; padding: 8px; color: var(--terminal-amber);">Status</th>
+                                <th style="text-align: left; padding: 8px; color: var(--terminal-amber);">Started</th>
+                                <th style="text-align: left; padding: 8px; color: var(--terminal-amber);">Duration</th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            ${executionDetails.map((exec, idx) => {
+                                const duration = exec.completed_at ?
+                                    Math.round((new Date(exec.completed_at) - new Date(exec.started_at)) / 1000) + 's' :
+                                    'Running...';
+                                return `
+                                    <tr style="border-bottom: 1px solid #003300;">
+                                        <td style="padding: 8px; color: var(--terminal-green);">Execution ${idx + 1}</td>
+                                        <td style="padding: 8px;"><span class="status ${exec.status}" style="font-size: 0.85em;">${exec.status}</span></td>
+                                        <td style="padding: 8px; color: var(--terminal-green);">${new Date(exec.started_at).toLocaleString()}</td>
+                                        <td style="padding: 8px; color: var(--terminal-green);">${duration}</td>
+                                    </tr>
+                                `;
+                            }).join('')}
+                        </tbody>
+                    </table>
+                </div>
+            `;
+
+            // Side-by-side output comparison
+            comparisonHtml += `
+                <div style="background: rgba(0, 255, 65, 0.05); border: 2px solid var(--terminal-green); padding: 15px;">
+                    <h3 style="margin-top: 0; color: var(--terminal-amber);">Output Comparison</h3>
+                    <div style="display: grid; grid-template-columns: repeat(${executionDetails.length}, 1fr); gap: 15px;">
+                        ${executionDetails.map((exec, idx) => {
+                            const logs = typeof exec.logs === 'string' ? JSON.parse(exec.logs) : exec.logs;
+                            const resultLog = logs.find(l => l.action === 'command_result');
+                            const stdout = resultLog?.stdout || 'No output';
+                            const stderr = resultLog?.stderr || '';
+
+                            return `
+                                <div style="border: 2px solid var(--terminal-green); background: #000;">
+                                    <div style="background: var(--bg-secondary); padding: 10px; border-bottom: 2px solid var(--terminal-green);">
+                                        <strong style="color: var(--terminal-amber);">Execution ${idx + 1}</strong>
+                                        <div style="font-size: 0.85em; color: var(--terminal-green);">
+                                            ${exec.workflow_name || '[Quick Command]'}
+                                        </div>
+                                    </div>
+                                    <div style="padding: 12px;">
+                                        ${stdout ? `
+                                            <div style="margin-bottom: 10px;">
+                                                <div style="color: var(--terminal-amber); font-weight: bold; margin-bottom: 5px;">STDOUT:</div>
+                                                <pre style="margin: 0; color: var(--terminal-green); font-size: 0.85em; max-height: 400px; overflow-y: auto; white-space: pre-wrap;">${escapeHtml(stdout)}</pre>
+                                            </div>
+                                        ` : ''}
+                                        ${stderr ? `
+                                            <div>
+                                                <div style="color: #ff4444; font-weight: bold; margin-bottom: 5px;">STDERR:</div>
+                                                <pre style="margin: 0; color: #ff4444; font-size: 0.85em; max-height: 200px; overflow-y: auto; white-space: pre-wrap;">${escapeHtml(stderr)}</pre>
+                                            </div>
+                                        ` : ''}
+                                    </div>
+                                </div>
+                            `;
+                        }).join('')}
+                    </div>
+                </div>
+            `;
+
+            // Diff analysis (simple line-by-line comparison for 2 executions)
+            if (executionDetails.length === 2) {
+                const logs1 = typeof executionDetails[0].logs === 'string' ? JSON.parse(executionDetails[0].logs) : executionDetails[0].logs;
+                const logs2 = typeof executionDetails[1].logs === 'string' ? JSON.parse(executionDetails[1].logs) : executionDetails[1].logs;
+
+                const result1 = logs1.find(l => l.action === 'command_result');
+                const result2 = logs2.find(l => l.action === 'command_result');
+
+                const stdout1 = result1?.stdout || '';
+                const stdout2 = result2?.stdout || '';
+
+                const lines1 = stdout1.split('\n');
+                const lines2 = stdout2.split('\n');
+                const maxLines = Math.max(lines1.length, lines2.length);
+
+                let diffLines = [];
+                let identicalCount = 0;
+                let differentCount = 0;
+
+                for (let i = 0; i < maxLines; i++) {
+                    const line1 = lines1[i] || '';
+                    const line2 = lines2[i] || '';
+
+                    if (line1 === line2) {
+                        identicalCount++;
+                        diffLines.push(`<div style="color: #666; padding: 2px;">${i+1}: ${escapeHtml(line1) || '(empty)'}</div>`);
+                    } else {
+                        differentCount++;
+                        diffLines.push(`
+                            <div style="background: rgba(255, 176, 0, 0.1); border-left: 3px solid var(--terminal-amber); padding: 2px; margin: 2px 0;">
+                                <div style="color: var(--terminal-green);">${i+1} [Exec 1]: ${escapeHtml(line1) || '(empty)'}</div>
+                                <div style="color: var(--terminal-amber);">${i+1} [Exec 2]: ${escapeHtml(line2) || '(empty)'}</div>
+                            </div>
+                        `);
+                    }
+                }
+
+                comparisonHtml += `
+                    <div style="background: rgba(0, 255, 65, 0.05); border: 2px solid var(--terminal-green); padding: 15px;">
+                        <h3 style="margin-top: 0; color: var(--terminal-amber);">Diff Analysis</h3>
+                        <div style="margin-bottom: 10px; font-family: var(--font-mono); font-size: 0.9em;">
+                            <span style="color: var(--terminal-green);">✓ Identical lines: ${identicalCount}</span> |
+                            <span style="color: var(--terminal-amber);">≠ Different lines: ${differentCount}</span>
+                        </div>
+                        <div style="background: #000; border: 2px solid var(--terminal-green); padding: 10px; max-height: 400px; overflow-y: auto; font-family: var(--font-mono); font-size: 0.85em;">
+                            ${diffLines.join('')}
+                        </div>
+                    </div>
+                `;
+            }
+
+            comparisonHtml += '</div>';
+
+            document.getElementById('compareContent').innerHTML = comparisonHtml;
+            document.getElementById('compareExecutionsModal').classList.add('show');
+        }
+
         async function loadMoreExecutions() {
             executionOffset += executionLimit;
             await loadExecutions(true);