diff --git a/static_src/elements/framework/mr-pref-toggle/mr-pref-toggle.test.js b/static_src/elements/framework/mr-pref-toggle/mr-pref-toggle.test.js
new file mode 100644
index 0000000..b6dbb41
--- /dev/null
+++ b/static_src/elements/framework/mr-pref-toggle/mr-pref-toggle.test.js
@@ -0,0 +1,86 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'sinon';
+import {assert} from 'chai';
+import {MrPrefToggle} from './mr-pref-toggle.js';
+import {prpcClient} from 'prpc-client-instance.js';
+
+let element;
+
+describe('mr-pref-toggle', () => {
+  beforeEach(() => {
+    element = document.createElement('mr-pref-toggle');
+    element.label = 'Code';
+    element.title = 'Code font';
+    element.prefName = 'code_font';
+    document.body.appendChild(element);
+    sinon.stub(prpcClient, 'call').returns(Promise.resolve({}));
+    window.ga = sinon.stub();
+  });
+
+  afterEach(() => {
+    document.body.removeChild(element);
+    prpcClient.call.restore();
+  });
+
+  it('initializes', () => {
+    assert.instanceOf(element, MrPrefToggle);
+  });
+
+  it('toggling does not save when user is not logged in', async () => {
+    element.userDisplayName = undefined;
+    element.prefs = new Map([]);
+
+    await element.updateComplete;
+
+    const chopsToggle = element.shadowRoot.querySelector('chops-toggle');
+    chopsToggle.click();
+    await element.updateComplete;
+
+    sinon.assert.notCalled(prpcClient.call);
+
+    assert.isTrue(element.prefs.get('code_font'));
+  });
+
+  it('toggling to true saves result', async () => {
+    element.userDisplayName = 'test@example.com';
+    element.prefs = new Map([['code_font', false]]);
+
+    await element.updateComplete;
+
+    const chopsToggle = element.shadowRoot.querySelector('chops-toggle');
+
+    chopsToggle.click(); // Toggle it on.
+    await element.updateComplete;
+
+    sinon.assert.calledWith(
+        prpcClient.call,
+        'monorail.Users',
+        'SetUserPrefs',
+        {prefs: [{name: 'code_font', value: 'true'}]});
+
+    assert.isTrue(element.prefs.get('code_font'));
+  });
+
+  it('toggling to false saves result', async () => {
+    element.userDisplayName = 'test@example.com';
+    element.prefs = new Map([['code_font', true]]);
+
+    await element.updateComplete;
+
+    const chopsToggle = element.shadowRoot.querySelector('chops-toggle');
+
+    chopsToggle.click(); // Toggle it off.
+    await element.updateComplete;
+
+    sinon.assert.calledWith(
+        prpcClient.call,
+        'monorail.Users',
+        'SetUserPrefs',
+        {prefs: [{name: 'code_font', value: 'false'}]});
+
+    assert.isFalse(element.prefs.get('code_font'));
+  });
+});