ApDex Score: The Truth No One Wants to Tell You


Share on LinkedIn

The Apdex scoring system was invented to introduce standardized scoring into the world of performance metrics. The online experience is in a continuous state of change, with more and more variables defining the user experience. Unfortunately, Apdex hasn’t evolved at the same pace.

The categorization of the user sentiment into Satisfied, Tolerating and Frustrated (more about this later) is no longer enough to understand the impact of modern Ad Tech and Martech stacks on performance and business metrics.


Apdex was developed by an alliance of companies as an open standard to report, benchmark, and track application performance. It serves as an easy indication method to translate application performance benchmarks to a simple comparison metric measuring responsiveness over a period of time.

The apdex index is based on three application responsiveness zones:

  1. Satisfied: The user is fully productive. This represents the time value (t seconds) below which users are not impeded by application response time.
  2. Tolerating: The user notices performance lagging within responses greater than the threshold (Apdex t), but continues the process.
  3. Frustrated: Performance with a response time greater than F seconds is unacceptable, and users may abandon the process.


1 – The Human Factor
The reality today is that every service you deploy comes with a performance cost. More often than not, these services cause user experience (UX) problems that affect visitor engagement and also complicate the mitigation process when these issues are identified. Apdex provides no added value here.

2 – Lack of Insights and Actionable Data
Response time values do not reveal the engagement levels of visitors. This lack of information only becomes more crucial when a greater number of samples are collected. Averaging the samples washes out significant details about frustration with slow response times, especially when time values are not uniform.

3 – The Growth of Third Party Integrations
Apdex scores are becoming more and more inaccurate due to their inability to attribute UX issues or success to a specific action, tool or solution. It simply doesn’t lead to any actionable insights. This is further exacerbated when significant parts of the code that renders the page is being delivered from off-page sources like code libraries or via third party integrations.

A good example is social-media giant Facebook, which operates as a Single Page Application (SPA). Single paged apps rely heavily on off-page code libraries.

Facebook uses its own coding language called React, which is no different. While you scroll through your news feed, new messages are pushed to you dynamically. Obviously, this would be very difficult to do if all the code was sitting directly on the page. Applying the Apdex philosophy to this complex ecosystem, which presents every user with a customized experience, has no benefit.

Just like you cannot assume you are healthy just by maintaining a healthy diet and looking for irregular symptoms, the modern online publisher cannot maximise business KPIs by just counting on Apdex. Just like you need to perform regular blood tests and dental work to stay healthy, your Tech stacks can only be optimized by monitoring third party services closely.

This is true especially for online publishers, who typically implement over 70 third party services in their Ad Tech and Martech stacks. These tags can have a massive impact on your website performance and can eventually become a significant factor in achieving maximum business revenue.

Once your web pages don’t load fast enough, they will probably leave your site with a negative impression, regardless of its Apdex score.


Please use comments to add value to the discussion. Maximum one link to an educational blog post or article. We will NOT PUBLISH brief comments like "good post," comments that mainly promote links, or comments with links to companies, products, or services.

Please enter your comment!
Please enter your name here