What is an Apdex Score?

Apdex, known as Application Performance Index, is an open standard solution used to measure user satisfaction with the response time of web applications and services. Apdex was developed by an alliance of companies to specify a uniform way for reporting and measuring the performance of an application. 

Apdex helps you turn your measurements into insights on how satisfied your users are in a human-friendly way. Apdex scores the satisfaction level in a numerical way with a fractional scale of 0 (user not satisfied) to 1 (user satisfied). With Apdex, you can improve your application's performance and track user satisfaction over a period of time. 

What is an Apdex Score

Why should you use an apdex score?

Calculating only application response time is not enough anymore. Viewed alone, they do not reveal whether people using your application are satisfied or frustrated with your service. Measuring your application performance and how it is affecting the user’s experience is quite critical for your business. 

In businesses, retaining customers and keeping them happy is as important as acquiring them. Apdex helps you understand and identify the impact on the application’s performance over time. Tracking your Apdex score will help you focus on improving your application’s performance and keeping your users happy. This turns them into loyal customers and helps you in customer retention.

How is the apdex score calculated?

Apdex score is calculated with the number of satisfied samples, plus half of the tolerated samples, divided by the total number of samples. You can look at the image on the right to understand it easily. The Apdex index is based on three application responsiveness zones:

  • Satisfied: A satisfied user with high application responsiveness.

  • Tolerating: A user with noticeable slow response from the application.

  • Frustrated: Unacceptable performance, leading the user to abandon the application.

For example, consider a system with 100 total users with a target response time of 3 seconds. Out of 100, 70 are satisfied users with response time below 3 seconds. 20 users are tolerating the slow response time between 3 to 12 seconds. Remaining 10 users abandoned the application with response time above 12 seconds. The apdex score will be 0.8.

What is a good Apdex score?


Different segments of users have different expectations for your application's performance. It’s crucial to create useful scores for the experiences your users expect. Your users will be willing to wait if they are getting something desirable at the other end, like processing of a successfully completed transaction. In other areas, where they are not enjoying the process, it is crucial to maintain a high apdex score. 

Generally, an excellent score falls in 1.00 - 0.94. A good score comes around 0.93 - 0.85. Fair score is between 0.84 - 0.70 and the poor hits 0.69 to 0.49. Any score below is considered unacceptable and users may abandon the process.

How to improve your Apdex Score?

To improve your Apdex, define a benchmark response time for your application. Define the response time needed for each working part of your application. The faster your response time, the better and higher your Apdex Score will be.

The infrastructure design of your application can affect your apdex score majorly. If your application is redesigned to communicate less over the network, the performance will improve significantly. Better performance will yield more satisfied users and a higher apdex score.

With Freshping, you can define a benchmark response time for your monitoring checks. Freshping calculates the apdex score for each of your checks and helps you track the performance against the set threshold. With the apdex score, it is visible to see which area of your application needs improvement. The best part is, you can try Freshping for free to monitor the apdex score beyond your website availability and status!