Perform A/B testing

Sample code

• Result: Performs A/B testing using a single URL.

• Language: JavaScript

• Sample code:

  // Determines the user group based on the Cookie header. Different content is returned for different group tags.
  async function handleRequest(request) {
    const NAME = 'var';
    const TEST_RESPONSE = new Response('A group'); // The Response content can also be replaced with the dynamic content of a fetch request.
    const CONTROL_RESPONSE = new Response('B group');
    // Determines the group based on the var field in the cookie.
    const cookie = request.headers.get('cookie');
    if (cookie && cookie.includes(`${NAME}=B group`)) {
      return CONTROL_RESPONSE;
    } else if (cookie && cookie.includes(`${NAME}=A group`)) {
      return TEST_RESPONSE;
    } 
    else {
      // If no cookie exists, select a group.    const group = Math.random() < 0.5 ? 'A group' : 'B group';
      const response = group === 'B group' ? CONTROL_RESPONSE : TEST_RESPONSE;
      response.headers.append('Set-Cookie', `${NAME}=${group}; path=/`);
      return response;
    }
  }
  
  export default {
    fetch(request) {
      return handleRequest(request);
    }
  }
  

Deployment result

Visit the URL of the edge function or your configured routing address in a browser. If the browser does not have a cookie, a group is randomly selected:

• If group A is labeled, the response for group A is returned.

• If group B is labeled, the response for group B is returned.