diff --git a/CHANGELOG.md b/CHANGELOG.md
index fc02a31..6590be1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 2025-12-29: v2.7.0
+
+- Added event `embedSize`
+
 ## 2025-10-22: v2.6.0
 
 - Added support for new locales: Danish (`da`), Finnish (`fi`), Filipino (`fil`), French Canadian (`fr-CA`), Hindi (`hi`), Indonesian (`id`), Malay (`ms`), Norwegian Bokmål (`nb`), Traditional Chinese Hong Kong (`zh-HK`), and Traditional Chinese Taiwan (`zh-TW`)
diff --git a/karma.conf.js b/karma.conf.js
index ab6642f..f3b4cb0 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -22,6 +22,7 @@ module.exports = config => {
         FLAT_EMBED_QUARTET_SCORE: process.env.FLAT_EMBED_QUARTET_SCORE,
         FLAT_EMBED_PRIVATE_LINK_SCORE: process.env.FLAT_EMBED_PRIVATE_LINK_SCORE,
         FLAT_EMBED_PRIVATE_LINK_SHARING_KEY: process.env.FLAT_EMBED_PRIVATE_LINK_SHARING_KEY,
+        FLAT_EMBED_NEW_DISPLAY: process.env.FLAT_EMBED_NEW_DISPLAY,
       },
     },
     reporters: ['mocha'],
diff --git a/package.json b/package.json
index 4950518..3a11f68 100644
--- a/package.json
+++ b/package.json
@@ -42,10 +42,13 @@
   "scripts": {
     "clean": "rm build/*",
     "build": "tsc && vite build",
-    "test": "tsc && pnpm run biome:check && npm run test:karma",
+    "test": "tsc && pnpm run biome:check && npm run test:karma:all-displays",
     "biome:check": "biome check .",
     "biome:fix": "biome check --write .",
     "test:karma": "karma start --single-run",
+    "test:karma:old-display": "karma start --single-run",
+    "test:karma:new-display": "FLAT_EMBED_NEW_DISPLAY=true karma start --single-run",
+    "test:karma:all-displays": "npm run test:karma:old-display && npm run test:karma:new-display",
     "test:karma-watch": "karma start --single-run=false --auto-watch",
     "prepare": "husky",
     "generate:docs": "npx tsx scripts/update-version-in-docs.ts && npx tsx scripts/generate-api-docs.ts"
diff --git a/src/types/embedSize.ts b/src/types/embedSize.ts
new file mode 100644
index 0000000..588cc24
--- /dev/null
+++ b/src/types/embedSize.ts
@@ -0,0 +1,9 @@
+/**
+ * Embed size information
+ */
+export interface EmbedSize {
+  /** Total embed height in pixels */
+  height: number;
+  /** Total embed width in pixels */
+  width: number;
+}
diff --git a/src/types/events.ts b/src/types/events.ts
index f2acb35..c928d6b 100644
--- a/src/types/events.ts
+++ b/src/types/events.ts
@@ -15,6 +15,7 @@ export const EVENTS_NAMES = [
   'stop',
   'playbackPosition',
   'restrictedFeatureAttempt',
+  'embedSize',
 ] as const;
 
 /**
diff --git a/src/types/index.ts b/src/types/index.ts
index 8051534..91166a0 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -3,6 +3,7 @@
 export * from './cursorPosition';
 export * from './embedMessage';
 export * from './embedParameters';
+export * from './embedSize';
 export * from './events';
 export * from './measure';
 export * from './metronome';
diff --git a/test/integration/embed-integration.js b/test/integration/embed-integration.js
index b59d23b..e241c7c 100644
--- a/test/integration/embed-integration.js
+++ b/test/integration/embed-integration.js
@@ -24,6 +24,9 @@ describe('Integration - Embed', () => {
     }
   });
 
+  const USE_NEW_DISPLAY = window.__karma__.config.env.FLAT_EMBED_NEW_DISPLAY === 'true';
+  console.log('[embed-integration] USE_NEW_DISPLAY:', USE_NEW_DISPLAY);
+
   function createEmbedForScoreId(score, embedParams = {}) {
     const container = document.createElement('div');
     document.body.appendChild(container);
@@ -38,6 +41,7 @@ describe('Integration - Embed', () => {
       embedParams: {
         ...embedParams,
         appId: APP_ID,
+        ...(USE_NEW_DISPLAY && { newDisplay: true }),
       },
     });
 
@@ -733,6 +737,74 @@ describe('Integration - Embed', () => {
     });
   });
 
+  describe('Events - embedSize', () => {
+    // Note: New display (adagio-display) currently reports viewport dimensions via contentRect,
+    // not actual content dimensions. Height assertions are skipped for new display until
+    // adagio-display is updated to report actual content height.
+    it('should receive embedSize event with reasonable dimensions', done => {
+      const { embed, container } = createEmbedForScoreId(PUBLIC_SCORE);
+      container.style.width = '800px';
+
+      // Wait for score to be loaded before subscribing to embedSize
+      // This ensures the score has fully rendered before we check dimensions
+      embed.on('scoreLoaded', () => {
+        // Add a small delay to allow layout to stabilize (especially for new display)
+        setTimeout(() => {
+          let eventCount = 0;
+          embed.on('embedSize', data => {
+            eventCount++;
+            console.log(`[embedSize test] event #${eventCount}: height=${data.height}px, width=${data.width}px`);
+
+            assert.ok(typeof data.height === 'number', 'height is number');
+            assert.ok(typeof data.width === 'number', 'width is number');
+            // Height should be meaningful for a real score (not just iframe chrome)
+            // Skip height check for new display - it returns viewport height, not content height
+            if (!USE_NEW_DISPLAY) {
+              assert.ok(data.height > 500, `height should be > 500px, got ${data.height}px`);
+            }
+            assert.ok(data.width > 0, 'width > 0');
+            done();
+          });
+        }, 500);
+      });
+    });
+
+    // Skip resize test for new display - contentRect doesn't update on container resize
+    (USE_NEW_DISPLAY ? it.skip : it)('should emit new embedSize event on container resize', done => {
+      const { embed, container } = createEmbedForScoreId(PUBLIC_SCORE);
+      container.style.width = '800px';
+
+      // Wait for score to be loaded before subscribing to embedSize
+      embed.on('scoreLoaded', () => {
+        // Add a small delay to allow layout to stabilize (especially for new display)
+        setTimeout(() => {
+          let eventCount = 0;
+          let firstWidth = 0;
+
+          embed.on('embedSize', data => {
+            eventCount++;
+            console.log(`[embedSize resize test] event #${eventCount}: height=${data.height}px, width=${data.width}px`);
+
+            if (eventCount === 1) {
+              // First event after load
+              firstWidth = data.width;
+              assert.ok(data.height > 500, `initial height > 500px, got ${data.height}px`);
+              // Trigger resize after first event
+              setTimeout(() => {
+                console.log('[embedSize resize test] triggering resize to 500px');
+                container.style.width = '500px';
+              }, 200);
+            } else if (eventCount === 2) {
+              // Second event after resize
+              assert.ok(data.width < firstWidth, `width should decrease after resize: ${data.width} < ${firstWidth}`);
+              done();
+            }
+          });
+        }, 500);
+      });
+    });
+  });
+
   describe('Parts display', () => {
     it('should get all the parts by default', async () => {
       const { embed } = createEmbedForScoreId(QUARTET_SCORE);
diff --git a/test/manual/test-embedSize.html b/test/manual/test-embedSize.html
new file mode 100644
index 0000000..0c6201e
--- /dev/null
+++ b/test/manual/test-embedSize.html
@@ -0,0 +1,203 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Test embedSize Event</title>
+  <style>
+    body {
+      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+      margin: 20px;
+    }
+    #embed-container {
+      width: 100%;
+      border: 1px solid #ccc;
+    }
+    #embed-container iframe {
+      display: block; /* Remove inline spacing */
+    }
+    #log {
+      margin-top: 20px;
+      padding: 10px;
+      background: #f5f5f5;
+      border-radius: 4px;
+      font-family: monospace;
+      white-space: pre-wrap;
+      max-height: 200px;
+      overflow-y: auto;
+    }
+    .controls {
+      margin-bottom: 15px;
+      display: flex;
+      gap: 10px;
+      flex-wrap: wrap;
+    }
+    .controls-group {
+      border: 1px solid #ddd;
+      padding: 8px 12px;
+      border-radius: 4px;
+      display: flex;
+      gap: 8px;
+      align-items: center;
+    }
+    .controls-group label {
+      font-weight: bold;
+      font-size: 12px;
+      color: #666;
+    }
+    button {
+      padding: 8px 16px;
+    }
+    button.active {
+      background: #4CAF50;
+      color: white;
+    }
+    .size-info {
+      margin-bottom: 15px;
+      padding: 10px;
+      background: #e8f4e8;
+      border-radius: 4px;
+      font-family: monospace;
+    }
+    .mode-info {
+      margin-bottom: 15px;
+      padding: 10px;
+      background: #e8e8f4;
+      border-radius: 4px;
+      font-family: monospace;
+    }
+  </style>
+</head>
+<body>
+  <h1>embedSize Event Test</h1>
+
+  <div class="controls">
+    <div class="controls-group">
+      <label>Actions:</label>
+      <button onclick="clearLog()">Clear Log</button>
+      <button onclick="location.reload()">Reload</button>
+    </div>
+    <div class="controls-group">
+      <label>Width:</label>
+      <button onclick="resizeContainer(600)">600px</button>
+      <button onclick="resizeContainer(800)">800px</button>
+      <button onclick="resizeContainer('100%')">100%</button>
+    </div>
+    <div class="controls-group">
+      <label>Layout:</label>
+      <button onclick="switchMode('responsive')" id="btn-responsive">Responsive</button>
+      <button onclick="switchMode('page')" id="btn-page">Page</button>
+      <button onclick="switchMode('track')" id="btn-track">Track</button>
+    </div>
+    <div class="controls-group">
+      <label>Display:</label>
+      <button onclick="switchDisplay(false)" id="btn-old-display">Old</button>
+      <button onclick="switchDisplay(true)" id="btn-new-display">New</button>
+    </div>
+  </div>
+
+  <div class="mode-info" id="mode-info">
+    Mode: loading...
+  </div>
+
+  <div class="size-info" id="size-info">
+    Iframe size: waiting for embedSize event...
+  </div>
+
+  <div id="embed-container"></div>
+
+  <h3>Event Log:</h3>
+  <div id="log"></div>
+
+  <script src="../../dist/flat-embed.mjs" type="module"></script>
+  <script type="module">
+    import Embed from '../../dist/flat-embed.mjs';
+
+    const log = document.getElementById('log');
+    const sizeInfo = document.getElementById('size-info');
+    const modeInfo = document.getElementById('mode-info');
+    const container = document.getElementById('embed-container');
+
+    // Get params from URL
+    const urlParams = new URLSearchParams(window.location.search);
+    const layout = urlParams.get('layout') || 'responsive';
+    const newDisplay = urlParams.get('newDisplay') === 'true';
+
+    // Update mode info
+    modeInfo.textContent = `Layout: ${layout} | Display: ${newDisplay ? 'new' : 'old'}`;
+
+    // Highlight active buttons
+    document.getElementById(`btn-${layout}`)?.classList.add('active');
+    document.getElementById(newDisplay ? 'btn-new-display' : 'btn-old-display')?.classList.add('active');
+
+    function addLog(message) {
+      const time = new Date().toLocaleTimeString();
+      log.textContent += `[${time}] ${message}\n`;
+      log.scrollTop = log.scrollHeight;
+    }
+
+    window.clearLog = function() {
+      log.textContent = '';
+    };
+
+    window.resizeContainer = function(width) {
+      const widthStr = typeof width === 'number' ? `${width}px` : width;
+      container.style.width = widthStr;
+      addLog(`Container width set to ${widthStr}`);
+    };
+
+    window.switchMode = function(newLayout) {
+      const params = new URLSearchParams(window.location.search);
+      params.set('layout', newLayout);
+      window.location.search = params.toString();
+    };
+
+    window.switchDisplay = function(useNew) {
+      const params = new URLSearchParams(window.location.search);
+      params.set('newDisplay', useNew ? 'true' : 'false');
+      window.location.search = params.toString();
+    };
+
+    addLog(`Creating embed with layout=${layout}, newDisplay=${newDisplay}...`);
+
+    const embedParams = {
+      appId: '58f0ee6053674e68c81e5646',
+      controlsFloating: false,
+      layout: layout,
+    };
+
+    if (newDisplay) {
+      embedParams['newDisplay'] = true;
+    }
+
+    const embed = new Embed('embed-container', {
+      score: '56ae21579a127715a02901a6',
+      // score: '655421147ae4155c831a5dbe',
+      // baseUrl: 'https://flat.ovh:3000/embed',
+      embedParams: embedParams
+    });
+
+    // Listen for ready
+    embed.ready().then(() => {
+      addLog('Embed ready!');
+    });
+
+    // Listen for scoreLoaded
+    embed.on('scoreLoaded', () => {
+      addLog('scoreLoaded event received');
+    });
+
+    // Listen for embedSize and auto-resize iframe height
+    embed.on('embedSize', (data) => {
+      addLog(`embedSize: ${data.width}px × ${data.height}px`);
+
+      // Set iframe height to match content - no scrollbars!
+      embed.element.style.height = `${data.height}px`;
+
+      sizeInfo.textContent = `Iframe size: ${data.width}px × ${data.height}px (auto-adjusted)`;
+    });
+
+    addLog('Event listeners registered, waiting for events...');
+  </script>
+</body>
+</html>