diff --git a/website/playground/new-samples/all.js b/website/playground/new-samples/all.js
index 06323f21..004108a4 100644
--- a/website/playground/new-samples/all.js
+++ b/website/playground/new-samples/all.js
@@ -156,6 +156,12 @@
 			id: 'extending-language-services-hover-provider-example',
 			path: 'extending-language-services/hover-provider-example'
 		},
+		{
+			chapter: 'Extending Language Services',
+			name: 'Model markers example',
+			id: 'extending-language-services-model-markers-example',
+			path: 'extending-language-services/model-markers-example'
+		},
 		{
 			chapter: 'Extending Language Services',
 			name: 'Semantic tokens provider example',
diff --git a/website/playground/new-samples/extending-language-services/model-markers-example/sample.css b/website/playground/new-samples/extending-language-services/model-markers-example/sample.css
new file mode 100644
index 00000000..e69de29b
diff --git a/website/playground/new-samples/extending-language-services/model-markers-example/sample.html b/website/playground/new-samples/extending-language-services/model-markers-example/sample.html
new file mode 100644
index 00000000..75b9b160
--- /dev/null
+++ b/website/playground/new-samples/extending-language-services/model-markers-example/sample.html
@@ -0,0 +1 @@
+<div id="container" style="height: 100%"></div>
diff --git a/website/playground/new-samples/extending-language-services/model-markers-example/sample.js b/website/playground/new-samples/extending-language-services/model-markers-example/sample.js
new file mode 100644
index 00000000..010f6d05
--- /dev/null
+++ b/website/playground/new-samples/extending-language-services/model-markers-example/sample.js
@@ -0,0 +1,48 @@
+function validate(model) {
+	const markers = [];
+	// lines start at 1
+	for (let i = 1; i < model.getLineCount() + 1; i++) {
+		const range = {
+			startLineNumber: i,
+			startColumn: 1,
+			endLineNumber: i,
+			endColumn: model.getLineLength(i) + 1
+		};
+		const content = model.getValueInRange(range).trim();
+		const number = Number(content);
+		if (Number.isNaN(number)) {
+			markers.push({
+				message: 'not a number',
+				severity: monaco.MarkerSeverity.Error,
+				startLineNumber: range.startLineNumber,
+				startColumn: range.startColumn,
+				endLineNumber: range.endLineNumber,
+				endColumn: range.endColumn
+			});
+		} else if (!Number.isInteger(number)) {
+			markers.push({
+				message: 'not an integer',
+				severity: monaco.MarkerSeverity.Warning,
+				startLineNumber: range.startLineNumber,
+				startColumn: range.startColumn,
+				endLineNumber: range.endLineNumber,
+				endColumn: range.endColumn
+			});
+		}
+	}
+	monaco.editor.setModelMarkers(model, 'owner', markers);
+}
+
+const value = `12345
+abcd
+234.56
+12345
+abcd
+234.56`;
+const uri = monaco.Uri.parse('inmemory://test');
+const model = monaco.editor.createModel(value, 'demoLanguage', uri);
+editor = monaco.editor.create(document.getElementById('container'), { model });
+validate(model);
+model.onDidChangeContent(() => {
+	validate(model);
+});