The Best & Worst Mobile ‘App-Lags’ in Europe, by Mobile Operator

  • Posted by Fran Cator
  • October 15, 2015 1:40 PM BST

15th October, London. New research by analyst firm STL Partners and Crittercism, a mobile app intelligence provider, shows staggering differences in ‘app-lag’ (the time it takes for an app to get a response over the Internet) across five major European countries and twenty mobile operators.


Performance for France, Germany, Italy, Spain and the UK:


  • Users in Italy had the worst app-lag experience overall, with Spain only slightly better.
  • Users in France had the best app-lag experience, with the UK second best.


Performance by individual operator:


  • Bouygues and Free in France lead the way in providing a good customer ‘app experience’.
  • Movistar in Spain and 3 in Italy showed the worst performance.


The study looked at ‘app lag’, the elapsed time between customers doing something within a mobile app, such as requesting an image from a server somewhere on the Internet, and the app’s response to this. The length of elapsed time is closely correlated with user satisfaction and behaviour – the quicker the response the happier people are and the longer they spend on the app. The technical term for this type of delay is ‘roundtrip latency’, and it is a clear and meaningful measure of how network performance affects customers (see below for more detail).


Users with the best operators only experience unsatisfactorily long delays on about one in ten requests, while the worst can see delays in as many as one in three.


“The difference between the best-performing and worst performing operators is very substantial. As customers become more aware of differences in latency or ‘app lags’ between operators, it is likely to become a key factor for customers in the selection process. As things stand the best-performing operators have a major advantage and those at the bottom of the pile should be particularly concerned,” said Chris Barraclough, Partner at STL Partners and lead author of the report.


“We’re in an age where most customers use apps on their phones much more than they make calls, so delivering a good app experience will be increasingly important to mobile operators in driving market share and the quality of customers they attract,” added Barraclough.


Detailed results are available in the full research, including comparisons on a country-by-country, and operator-by-operator basis.


Further Details on the Research

The full report is available here:


More on the data and the methodology

Latency is increasingly recognised as a key driver of customer ‘app experience’ and by measuring latency from hundreds of millions of users and tens of thousands of applications, STL Partners and Crittercism show the relative performance of 20 leading mobile operators across France, Germany, Italy, Spain and the UK.


Using anonymised and aggregated data gathered from mobile subscribers’ app usage provided by Crittercism which generates this data primarily to help app developers make better apps. STL Partners has analysed the actual ‘total roundtrip latency’ of major mobile operators across Europe. The data measures the time taken from the moment a user takes an action, such as pressing a button on a mobile device, to receiving a response – in effect, a packet arriving back and being processed by the application at the device. This is the best indication of customer app experience because it reflects a customer’s total ‘wait time’.


Results from August 2015 for both average latency and, more importantly, the proportion of requests made by users that experience an unsatisfactory response time (above 500 milliseconds or 0.5 seconds), vary widely by country and by operator. Overall France and the UK have the best app latency performance in Europe with only 12% and 14% of requests above 500ms. At the other extreme, users in Spain and Italy experience 23% and 25% of ‘slow’ requests respectively. This is highly likely to translate into material differences in customer app experience between countries.


Results for individual operators are equally diverse. Subscribers of Bouygues and Free in France experience only 10% of app requests above 500ms while those of Movistar in Spain and 3 Italy suffer a whopping 30% and 32% respectively.


“App responsiveness is very important. For example, tests by Google as long ago as 2006 showed that an additional 500ms of latency reduced click-through rates and advertising revenue by 20%. With this data entering the public domain, it is only a matter of time before users become aware of the relative responsiveness of different mobile operators and that could have a very big impact on customer acquisition and retention. If you know you can get a better app performance by switching operator that would be a big pull for many users. The operators with the poorest performance in each market should be concerned about this.”


“While performance is clearly linked to geography – with many of the best-performing operators in France and the UK – there is still wide variation between operators within many markets. For example, 3’s performance is materially worse than the other operators in the UK and Movistar’s latency performance is similarly poor relative to that of Orange, Yoigo and Vodafone in Spain.”


Report contact: Chris Barraclough. +44 (0) 207 247 5003. Email:


Press contact: Meghan Matheny on behalf of Crittercism

(317) 806-1900 ext. 115