Apptimize supports client-side web, mobile-web, and hybrid mobile app testing through our JavaScript SDK.

At this time, the JavaScript SDK supports programmatic experimentation (Dynamic Variables and Code Blocks), but does not allow you to make visual changes using the Visual Editor.

EU Cloud Site

Use the configAttributes flag to set your Apptimize region to EUCS if you are integrated in our EU Cloud site.

var apptimizeAppKey = 'YOUR_APP_KEY';
var configAttributes = {
    'apptimize_region': 'eucs',

Apptimize.setup(apptimizeAppKey, configAttributes);

SDK Installation

Sign in to the Apptimize dashboard. You’ll see a welcome page that asks for the name of your app. After entering all your info, you’ll see these installation instructions again.

You can find our latest JavaScript API Documentation here.

Install with NPM

Install the SDK from the command-line with npm i @apptimize/apptimize-web-sdk

Then, include Apptimize in your app using import:

import Apptimize from '@apptimize/apptimize-web-sdk';
// You can also use 'require' for a non-ES6 option.
// var Apptimize = require('@apptimize/apptimize-web-sdk');

Our package can be found on npm here.

Install Directly

The SDK is also available as a downloadable package which comes bundled with all external dependencies.

  1. Download the latest JavaScript SDK from the SDK Download page.

  2. Copy the SDK to your project directory, like an include or scripts directory.

  3. Reference the SDK in your code: <script src="<path-to-sdk>/apptimize-js-client-<version>.bundle.min.js"></script>.

Including the script will make the Apptimize API available as window.Apptimize.

Initializing Apptimize

To initialize Apptimize, call the setup() method with the App Key associated with your app, which can be found in the Install tab of your Dashboard.

Synchronous and Asynchronous Loading

To ensure the best experience for your end users, we recommend waiting to display page content until Apptimize has been fully loaded and initialized. This will prevent potential issues with users seeing multiple variants (“flickering” of visual elements) and will prevent situations where an outsized percentage of users are placed in the baseline variant because the experiment data hasn’t been fully received and processed by the SDK.

The sample code below shows how to use setOnApptimizeInitializedCallback() to determine when Apptimize setup and initialization is complete.

// Create a function that will be executed whenever new Apptimize metadata is downloaded
function onApptimizeInitialized(){
    console.log("Apptimize setup and initialization complete");
    Apptimize.track("Apptimize Initialized");
    // Set a flag to indicate Apptimize data is available and content can be displayed


Single-Page Web Apps

The Apptimize JavaScript SDK supports popular single-page web application platforms such as React and Angular.

A simple example of an implementation of Apptimize in a basic React application is shown below as a demonstration. In this example, Apptimize has been installed using npm i @apptimize/apptimize-web-sdk as described above.

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
import Apptimize from '@apptimize/apptimize-web-sdk'

class App extends Component {
    constructor(props) {
        this.state = {
            isApptimizeSdkReady: false,
            variantString: null

    componentDidMount() {
        // Create a function that will be executed when Apptimize sdk has been initialized
        let onApptimizeInitialized = function() {
                isApptimizeSdkReady: true,
                // Set dynamic variable values
                variantString: Apptimize.getString("My Dynamic Variable", "Default value"),

    render() {
        if (!this.state.isApptimizeSdkReady) {
            return null;
        return (
                    Dynamic Variable Value: {this.state.variantString}

export default App;