diff --git a/index.html b/index.html
index 770a67d..7b49148 100644
--- a/index.html
+++ b/index.html
@@ -823,7 +823,7 @@
     </div>
 
     <!-- Settings Modal -->
-    <div id="settings-modal" class="modal" style="display: none;">
+    <div id="settings-modal" class="modal" style="display: none;" x-data="settingsPanel()">
         <div class="modal-content" style="max-width: 600px; height: auto; max-height: 85vh;">
             <div class="modal-header">
                 <span class="modal-title">Settings</span>
@@ -838,7 +838,7 @@
                         <div class="settings-item">
                             <label class="settings-label" for="setting-ui-theme">Theme</label>
                             <div class="settings-control">
-                                <select id="setting-ui-theme" class="settings-select">
+                                <select id="setting-ui-theme" class="settings-select" x-model="uiTheme">
                                     <option value="light">Light</option>
                                     <option value="experimental">Dark (Experimental)</option>
                                 </select>
@@ -853,15 +853,15 @@
                         <div class="settings-item">
                             <label class="settings-label" for="setting-font-size">Font Size</label>
                             <div class="settings-control">
-                                <input type="range" id="setting-font-size" min="10" max="18" step="1" value="12" class="settings-slider" />
-                                <span class="settings-value" id="setting-font-size-value">12px</span>
+                                <input type="range" id="setting-font-size" min="10" max="18" step="1" class="settings-slider" x-model.number="fontSize" />
+                                <span class="settings-value" id="setting-font-size-value" x-text="fontSize + 'px'"></span>
                             </div>
                         </div>
 
                         <div class="settings-item">
                             <label class="settings-label" for="setting-editor-theme">Editor Theme</label>
                             <div class="settings-control">
-                                <select id="setting-editor-theme" class="settings-select">
+                                <select id="setting-editor-theme" class="settings-select" x-model="editorTheme">
                                     <option value="vs-light">Light</option>
                                     <option value="vs-dark">Dark</option>
                                     <option value="hc-black">High Contrast</option>
@@ -872,7 +872,7 @@
                         <div class="settings-item">
                             <label class="settings-label" for="setting-tab-size">Tab Size</label>
                             <div class="settings-control">
-                                <select id="setting-tab-size" class="settings-select">
+                                <select id="setting-tab-size" class="settings-select" x-model.number="tabSize">
                                     <option value="2">2 spaces</option>
                                     <option value="4">4 spaces</option>
                                     <option value="8">8 spaces</option>
@@ -882,21 +882,21 @@
 
                         <div class="settings-item">
                             <label class="settings-label">
-                                <input type="checkbox" id="setting-minimap" class="settings-checkbox" />
+                                <input type="checkbox" id="setting-minimap" class="settings-checkbox" x-model="minimap" />
                                 Show minimap
                             </label>
                         </div>
 
                         <div class="settings-item">
                             <label class="settings-label">
-                                <input type="checkbox" id="setting-word-wrap" class="settings-checkbox" checked />
+                                <input type="checkbox" id="setting-word-wrap" class="settings-checkbox" x-model="wordWrap" />
                                 Enable word wrap
                             </label>
                         </div>
 
                         <div class="settings-item">
                             <label class="settings-label">
-                                <input type="checkbox" id="setting-line-numbers" class="settings-checkbox" checked />
+                                <input type="checkbox" id="setting-line-numbers" class="settings-checkbox" x-model="lineNumbers" />
                                 Show line numbers
                             </label>
                         </div>
@@ -909,8 +909,8 @@
                         <div class="settings-item">
                             <label class="settings-label" for="setting-render-debounce">Render Delay</label>
                             <div class="settings-control">
-                                <input type="range" id="setting-render-debounce" min="300" max="3000" step="100" value="1500" class="settings-slider" />
-                                <span class="settings-value" id="setting-render-debounce-value">1500ms</span>
+                                <input type="range" id="setting-render-debounce" min="300" max="3000" step="100" class="settings-slider" x-model.number="renderDebounce" />
+                                <span class="settings-value" id="setting-render-debounce-value" x-text="renderDebounce + 'ms'"></span>
                             </div>
                             <div class="settings-hint">Delay before visualization updates while typing</div>
                         </div>
@@ -923,7 +923,7 @@
                         <div class="settings-item">
                             <label class="settings-label" for="setting-date-format">Date Format</label>
                             <div class="settings-control">
-                                <select id="setting-date-format" class="settings-select">
+                                <select id="setting-date-format" class="settings-select" x-model="dateFormat">
                                     <option value="smart">Smart (relative times)</option>
                                     <option value="locale">Locale (browser default)</option>
                                     <option value="iso">ISO 8601</option>
@@ -932,10 +932,10 @@
                             </div>
                         </div>
 
-                        <div class="settings-item" id="custom-date-format-item" style="display: none;">
+                        <div class="settings-item" id="custom-date-format-item" x-show="showCustomDateFormat">
                             <label class="settings-label" for="setting-custom-date-format">Custom Format</label>
                             <div class="settings-control">
-                                <input type="text" id="setting-custom-date-format" class="settings-input" value="yyyy-MM-dd HH:mm" placeholder="yyyy-MM-dd HH:mm" />
+                                <input type="text" id="setting-custom-date-format" class="settings-input" placeholder="yyyy-MM-dd HH:mm" x-model="customDateFormat" />
                             </div>
                             <div class="settings-hint">
                                 Tokens: yyyy (year), MM (month), dd (day), HH (24h), hh (12h), mm (min), ss (sec), a/A (am/pm)
@@ -945,9 +945,19 @@
 
                     <!-- Actions -->
                     <div class="settings-actions">
-                        <button class="btn btn-modal primary" id="settings-apply-btn" title="Apply and save settings">Apply</button>
-                        <button class="btn btn-modal" id="settings-reset-btn" title="Reset to default settings">Reset to Defaults</button>
-                        <button class="btn btn-modal" id="settings-cancel-btn" title="Cancel without saving">Cancel</button>
+                        <button class="btn btn-modal primary"
+                                id="settings-apply-btn"
+                                @click="apply()"
+                                :disabled="!isDirty"
+                                title="Apply and save settings">Apply</button>
+                        <button class="btn btn-modal"
+                                id="settings-reset-btn"
+                                @click="reset()"
+                                title="Reset to default settings">Reset to Defaults</button>
+                        <button class="btn btn-modal"
+                                id="settings-cancel-btn"
+                                @click="cancel()"
+                                title="Cancel without saving">Cancel</button>
                     </div>
                 </div>
             </div>
diff --git a/project-docs/alpine-migration-plan.md b/project-docs/alpine-migration-plan.md
index df2652c..984e3ca 100644
--- a/project-docs/alpine-migration-plan.md
+++ b/project-docs/alpine-migration-plan.md
@@ -139,28 +139,50 @@ Incremental migration of Astrolabe from vanilla JavaScript to Alpine.js for reac
 
 ---
 
-## Phase 4: Settings Modal
+## Phase 4: Settings Modal ✅ COMPLETE
 
-**Status**: Planned
-**Files**: `src/js/app.js`, `index.html`
+**Status**: Done
+**Files**: `src/js/user-settings.js`, `index.html`, `src/js/app.js`
 
-### What to Convert
+### What Was Converted
 
-Settings form with multiple inputs and apply/reset functionality.
+- Settings modal form with all input controls using `x-model`
+- Apply/Reset/Cancel buttons with `@click` handlers
+- Computed `isDirty` property to enable/disable Apply button
+- Conditional custom date format field with `x-show`
+- Slider value displays with `x-text`
+- All form state management moved to Alpine component
 
 ### Implementation Approach
 
-1. Create `settingsPanel()` component with settings state tracking
-2. Use `x-model` for all form inputs (theme, editor settings, date format)
-3. Add computed `isDirty` property to enable/disable Apply button
-4. Use `x-show` for conditional fields (custom date format)
-5. Remove manual event listeners from app.js
+1. Created `settingsPanel()` component in `user-settings.js` with form state tracking
+2. Used `x-model` (with `.number` modifier where needed) for all form inputs:
+   - Theme selects
+   - Font size and render debounce sliders
+   - Tab size select
+   - Checkboxes (minimap, word wrap, line numbers)
+   - Date format and custom format input
+3. Added computed `isDirty` getter to compare current vs. original state
+4. Added computed `showCustomDateFormat` getter for conditional field visibility
+5. Moved all apply/reset/cancel logic into Alpine component methods
+6. Removed vanilla event listeners and old `loadSettingsIntoUI()` / `applySettings()` functions
 
 ### What Stays Vanilla
 
-- AppSettings storage layer
-- Editor option updates
-- Theme application logic
+- Settings storage layer (getSettings, updateSettings, etc.)
+- Settings validation logic (validateSetting)
+- Editor option updates (applied from within Alpine component)
+- Theme application logic (applied from within Alpine component)
+- Modal open/close functions (simple ModalManager calls)
+
+### Key Learnings
+
+- Alpine component handles all form state reactivity
+- `isDirty` computed property automatically enables/disables Apply button
+- `x-model.number` modifier ensures numeric values for sliders and selects
+- `x-show` provides clean conditional rendering for custom date format field
+- All business logic (validation, saving, applying) stays in existing functions
+- Net code reduction: ~150 lines of manual DOM manipulation removed
 
 ---
 
@@ -261,7 +283,7 @@ Toast notification system with auto-dismiss.
 1. ✅ **Phase 1: Snippet Panel** - DONE
 2. ✅ **Phase 2: Dataset Manager** - DONE
 3. ✅ **Phase 3: View Mode Toggle** - DONE
-4. **Phase 4: Settings Modal** - Another modal, builds confidence
+4. ✅ **Phase 4: Settings Modal** - DONE
 5. **Phase 6: Meta Fields** - Before Chart Builder (simpler)
 6. **Phase 7: Panel Toggles** - Quick win
 7. **Phase 5: Chart Builder** - More complex, save for when confident
diff --git a/src/js/app.js b/src/js/app.js
index afb2251..adcf306 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -184,61 +184,12 @@ document.addEventListener('DOMContentLoaded', function () {
 
     // Settings Modal
     const settingsLink = document.getElementById('settings-link');
-    const settingsApplyBtn = document.getElementById('settings-apply-btn');
-    const settingsResetBtn = document.getElementById('settings-reset-btn');
-    const settingsCancelBtn = document.getElementById('settings-cancel-btn');
 
     if (settingsLink) {
         settingsLink.addEventListener('click', openSettingsModal);
     }
 
-    if (settingsCancelBtn) {
-        settingsCancelBtn.addEventListener('click', closeSettingsModal);
-    }
-
-    if (settingsApplyBtn) {
-        settingsApplyBtn.addEventListener('click', applySettings);
-    }
-
-    if (settingsResetBtn) {
-        settingsResetBtn.addEventListener('click', function() {
-            if (confirm('Reset all settings to defaults? This cannot be undone.')) {
-                resetSettings();
-                loadSettingsIntoUI();
-                Toast.show('Settings reset to defaults', 'success');
-            }
-        });
-    }
-
-
-    // Settings UI interactions
-    const fontSizeSlider = document.getElementById('setting-font-size');
-    const fontSizeValue = document.getElementById('setting-font-size-value');
-    if (fontSizeSlider && fontSizeValue) {
-        fontSizeSlider.addEventListener('input', function() {
-            fontSizeValue.textContent = this.value + 'px';
-        });
-    }
-
-    const renderDebounceSlider = document.getElementById('setting-render-debounce');
-    const renderDebounceValue = document.getElementById('setting-render-debounce-value');
-    if (renderDebounceSlider && renderDebounceValue) {
-        renderDebounceSlider.addEventListener('input', function() {
-            renderDebounceValue.textContent = this.value + 'ms';
-        });
-    }
-
-    const dateFormatSelect = document.getElementById('setting-date-format');
-    const customDateFormatItem = document.getElementById('custom-date-format-item');
-    if (dateFormatSelect && customDateFormatItem) {
-        dateFormatSelect.addEventListener('change', function() {
-            if (this.value === 'custom') {
-                customDateFormatItem.style.display = 'block';
-            } else {
-                customDateFormatItem.style.display = 'none';
-            }
-        });
-    }
+    // Settings buttons and UI interactions now handled by Alpine.js in settingsPanel() component
 
     // Dataset Manager
     const datasetsLink = document.getElementById('datasets-link');
@@ -567,160 +518,12 @@ function registerMonacoKeyboardShortcuts() {
         KeyboardActions.publishDraft);
 }
 
-// Settings modal functions (special handling for loading settings into UI)
+// Settings modal functions (simplified - most logic now in Alpine settingsPanel() component)
 function openSettingsModal() {
-    loadSettingsIntoUI();
     ModalManager.open('settings-modal');
+    // Settings will be loaded via Alpine's init() method
 }
 
 function closeSettingsModal() {
     ModalManager.close('settings-modal');
 }
-
-function loadSettingsIntoUI() {
-    const settings = getSettings();
-
-    // Appearance settings
-    const uiThemeSelect = document.getElementById('setting-ui-theme');
-    if (uiThemeSelect) {
-        uiThemeSelect.value = settings.ui.theme;
-    }
-
-    // Editor settings
-    const fontSizeSlider = document.getElementById('setting-font-size');
-    const fontSizeValue = document.getElementById('setting-font-size-value');
-    if (fontSizeSlider && fontSizeValue) {
-        fontSizeSlider.value = settings.editor.fontSize;
-        fontSizeValue.textContent = settings.editor.fontSize + 'px';
-    }
-
-    const editorThemeSelect = document.getElementById('setting-editor-theme');
-    if (editorThemeSelect) {
-        editorThemeSelect.value = settings.editor.theme;
-    }
-
-    const tabSizeSelect = document.getElementById('setting-tab-size');
-    if (tabSizeSelect) {
-        tabSizeSelect.value = settings.editor.tabSize;
-    }
-
-    const minimapCheckbox = document.getElementById('setting-minimap');
-    if (minimapCheckbox) {
-        minimapCheckbox.checked = settings.editor.minimap;
-    }
-
-    const wordWrapCheckbox = document.getElementById('setting-word-wrap');
-    if (wordWrapCheckbox) {
-        wordWrapCheckbox.checked = settings.editor.wordWrap === 'on';
-    }
-
-    const lineNumbersCheckbox = document.getElementById('setting-line-numbers');
-    if (lineNumbersCheckbox) {
-        lineNumbersCheckbox.checked = settings.editor.lineNumbers === 'on';
-    }
-
-    // Performance settings
-    const renderDebounceSlider = document.getElementById('setting-render-debounce');
-    const renderDebounceValue = document.getElementById('setting-render-debounce-value');
-    if (renderDebounceSlider && renderDebounceValue) {
-        renderDebounceSlider.value = settings.performance.renderDebounce;
-        renderDebounceValue.textContent = settings.performance.renderDebounce + 'ms';
-    }
-
-    // Formatting settings
-    const dateFormatSelect = document.getElementById('setting-date-format');
-    const customDateFormatItem = document.getElementById('custom-date-format-item');
-    if (dateFormatSelect) {
-        dateFormatSelect.value = settings.formatting.dateFormat;
-        if (customDateFormatItem) {
-            customDateFormatItem.style.display = settings.formatting.dateFormat === 'custom' ? 'block' : 'none';
-        }
-    }
-
-    const customDateFormatInput = document.getElementById('setting-custom-date-format');
-    if (customDateFormatInput) {
-        customDateFormatInput.value = settings.formatting.customDateFormat;
-    }
-}
-
-function applySettings() {
-    // Collect values from UI
-    const newSettings = {
-        'ui.theme': document.getElementById('setting-ui-theme').value,
-        'editor.fontSize': parseInt(document.getElementById('setting-font-size').value),
-        'editor.theme': document.getElementById('setting-editor-theme').value,
-        'editor.tabSize': parseInt(document.getElementById('setting-tab-size').value),
-        'editor.minimap': document.getElementById('setting-minimap').checked,
-        'editor.wordWrap': document.getElementById('setting-word-wrap').checked ? 'on' : 'off',
-        'editor.lineNumbers': document.getElementById('setting-line-numbers').checked ? 'on' : 'off',
-        'performance.renderDebounce': parseInt(document.getElementById('setting-render-debounce').value),
-        'formatting.dateFormat': document.getElementById('setting-date-format').value,
-        'formatting.customDateFormat': document.getElementById('setting-custom-date-format').value
-    };
-
-    // Validate settings
-    let hasErrors = false;
-    for (const [path, value] of Object.entries(newSettings)) {
-        const errors = validateSetting(path, value);
-        if (errors.length > 0) {
-            Toast.show(errors.join(', '), 'error');
-            hasErrors = true;
-            break;
-        }
-    }
-
-    if (hasErrors) {
-        return;
-    }
-
-    // Save settings
-    if (updateSettings(newSettings)) {
-        // Apply theme to document
-        const uiTheme = newSettings['ui.theme'];
-        document.documentElement.setAttribute('data-theme', uiTheme);
-
-        // Sync editor theme with UI theme
-        const editorTheme = uiTheme === 'experimental' ? 'vs-dark' : 'vs-light';
-        newSettings['editor.theme'] = editorTheme;
-
-        // Apply editor settings immediately
-        if (editor) {
-            editor.updateOptions({
-                fontSize: newSettings['editor.fontSize'],
-                theme: editorTheme,
-                tabSize: newSettings['editor.tabSize'],
-                minimap: { enabled: newSettings['editor.minimap'] },
-                wordWrap: newSettings['editor.wordWrap'],
-                lineNumbers: newSettings['editor.lineNumbers']
-            });
-        }
-
-        // Update the editor theme in settings
-        updateSetting('editor.theme', editorTheme);
-
-        // Update debounced render function
-        if (typeof updateRenderDebounce === 'function') {
-            updateRenderDebounce(newSettings['performance.renderDebounce']);
-        }
-
-        // Re-render snippet list to reflect date format changes
-        renderSnippetList();
-
-        // Update metadata display if a snippet is selected
-        if (window.currentSnippetId) {
-            const snippet = SnippetStorage.getSnippet(window.currentSnippetId);
-            if (snippet) {
-                document.getElementById('snippet-created').textContent = formatDate(snippet.created, true);
-                document.getElementById('snippet-modified').textContent = formatDate(snippet.modified, true);
-            }
-        }
-
-        Toast.show('Settings applied successfully', 'success');
-        closeSettingsModal();
-
-        // Track event
-        Analytics.track('settings-apply', 'Applied settings');
-    } else {
-        Toast.show('Failed to save settings', 'error');
-    }
-}
diff --git a/src/js/user-settings.js b/src/js/user-settings.js
index 371445e..bb002d3 100644
--- a/src/js/user-settings.js
+++ b/src/js/user-settings.js
@@ -222,3 +222,166 @@ function validateSetting(path, value) {
 
     return rules[path] ? rules[path]() : [];
 }
+
+// Alpine.js Component for settings panel
+// Thin wrapper - Alpine handles form state and reactivity, user-settings.js handles storage
+function settingsPanel() {
+    return {
+        // Form state (loaded from settings on open)
+        uiTheme: 'light',
+        fontSize: 12,
+        editorTheme: 'vs-light',
+        tabSize: 2,
+        minimap: false,
+        wordWrap: true,
+        lineNumbers: true,
+        renderDebounce: 1500,
+        dateFormat: 'smart',
+        customDateFormat: 'yyyy-MM-dd HH:mm',
+
+        // Original values for dirty checking
+        originalSettings: null,
+
+        // Initialize component with current settings
+        init() {
+            this.loadSettings();
+        },
+
+        // Load settings from storage into form
+        loadSettings() {
+            const settings = getSettings();
+            this.uiTheme = settings.ui.theme;
+            this.fontSize = settings.editor.fontSize;
+            this.editorTheme = settings.editor.theme;
+            this.tabSize = settings.editor.tabSize;
+            this.minimap = settings.editor.minimap;
+            this.wordWrap = settings.editor.wordWrap === 'on';
+            this.lineNumbers = settings.editor.lineNumbers === 'on';
+            this.renderDebounce = settings.performance.renderDebounce;
+            this.dateFormat = settings.formatting.dateFormat;
+            this.customDateFormat = settings.formatting.customDateFormat;
+
+            // Store original values for dirty checking
+            this.originalSettings = JSON.stringify(this.getCurrentFormState());
+        },
+
+        // Get current form state as object
+        getCurrentFormState() {
+            return {
+                uiTheme: this.uiTheme,
+                fontSize: this.fontSize,
+                editorTheme: this.editorTheme,
+                tabSize: this.tabSize,
+                minimap: this.minimap,
+                wordWrap: this.wordWrap,
+                lineNumbers: this.lineNumbers,
+                renderDebounce: this.renderDebounce,
+                dateFormat: this.dateFormat,
+                customDateFormat: this.customDateFormat
+            };
+        },
+
+        // Check if settings have been modified
+        get isDirty() {
+            return this.originalSettings !== JSON.stringify(this.getCurrentFormState());
+        },
+
+        // Show custom date format field when 'custom' is selected
+        get showCustomDateFormat() {
+            return this.dateFormat === 'custom';
+        },
+
+        // Apply settings and save
+        apply() {
+            const newSettings = {
+                'ui.theme': this.uiTheme,
+                'editor.fontSize': parseInt(this.fontSize),
+                'editor.theme': this.editorTheme,
+                'editor.tabSize': parseInt(this.tabSize),
+                'editor.minimap': this.minimap,
+                'editor.wordWrap': this.wordWrap ? 'on' : 'off',
+                'editor.lineNumbers': this.lineNumbers ? 'on' : 'off',
+                'performance.renderDebounce': parseInt(this.renderDebounce),
+                'formatting.dateFormat': this.dateFormat,
+                'formatting.customDateFormat': this.customDateFormat
+            };
+
+            // Validate settings
+            let hasErrors = false;
+            for (const [path, value] of Object.entries(newSettings)) {
+                const errors = validateSetting(path, value);
+                if (errors.length > 0) {
+                    Toast.show(errors.join(', '), 'error');
+                    hasErrors = true;
+                    break;
+                }
+            }
+
+            if (hasErrors) return;
+
+            // Save settings
+            if (updateSettings(newSettings)) {
+                // Apply theme to document
+                document.documentElement.setAttribute('data-theme', this.uiTheme);
+
+                // Sync editor theme with UI theme
+                const editorTheme = this.uiTheme === 'experimental' ? 'vs-dark' : 'vs-light';
+                newSettings['editor.theme'] = editorTheme;
+
+                // Apply editor settings immediately
+                if (editor) {
+                    editor.updateOptions({
+                        fontSize: newSettings['editor.fontSize'],
+                        theme: editorTheme,
+                        tabSize: newSettings['editor.tabSize'],
+                        minimap: { enabled: newSettings['editor.minimap'] },
+                        wordWrap: newSettings['editor.wordWrap'],
+                        lineNumbers: newSettings['editor.lineNumbers']
+                    });
+                }
+
+                // Update the editor theme in settings
+                updateSetting('editor.theme', editorTheme);
+
+                // Update debounced render function
+                if (typeof updateRenderDebounce === 'function') {
+                    updateRenderDebounce(newSettings['performance.renderDebounce']);
+                }
+
+                // Re-render snippet list to reflect date format changes
+                renderSnippetList();
+
+                // Update metadata display if a snippet is selected
+                if (window.currentSnippetId) {
+                    const snippet = SnippetStorage.getSnippet(window.currentSnippetId);
+                    if (snippet) {
+                        document.getElementById('snippet-created').textContent = formatDate(snippet.created, true);
+                        document.getElementById('snippet-modified').textContent = formatDate(snippet.modified, true);
+                    }
+                }
+
+                Toast.success('Settings applied successfully');
+                closeSettingsModal();
+
+                // Track event
+                Analytics.track('settings-apply', 'Applied settings');
+            } else {
+                Toast.error('Failed to save settings');
+            }
+        },
+
+        // Reset to defaults
+        reset() {
+            if (confirm('Reset all settings to defaults? This cannot be undone.')) {
+                resetSettings();
+                this.loadSettings();
+                Toast.success('Settings reset to defaults');
+            }
+        },
+
+        // Cancel changes and close modal
+        cancel() {
+            closeSettingsModal();
+        }
+    };
+}