HeadSpin Proposes Speed Optimizations as Perfect Makeup for Sephora


Overview and Methodology For Our Analysis




iPhone 8 Plus / AT&T / Palo Alto

Products Used:

HeadSpin Connected Intelligence Platform


  • Optimize connection reuse will have the highest impact
  • Review multiple 3rd party API calls SDKs that are causing slowdowns
  • Ensure there are fewer duplicate messages
  • HeadSpin analyzed the latest version of the Sephora iOS app on a real iPhone 8 Plus in Palo Alto, on the AT&T network.
  • NO SDK, code change or instrumentation was needed to run the remote performance sessions.
  • HeadSpin’s AI engine sifted through network traffic, client-side metrics, and videos of the test execution to find areas of poor user experience and performance bottlenecks.
  • Recommendations were provided for every issue that was surfaced.

User Reviews

Sephora is doing very well overall in terms of user ratings on the App Store.

HeadSpin looked at Sephora reviews in the App Store and found some users struggling with functional issues and technical errors.

Sephora ratings is currently 4.8/5 on the App Store.


Insights and Recommendations

HeadSpin’s proprietary AI technology analyzes and prioritizes the core issues impacting critical user journeys. Using computer vision techniques to quantify blank screens, time to interact, loading time, loading or buffering animations, and content quality, our AI models can automatically diagnose server-side issues whether they arise from infrastructure deployment issues, poor performance, or API errors. For a custom analysis of your app, request a Performance Insight report from HeadSpin. 

HeadSpin Performance Session (link)


Analysed KPIs

  Launch Time     18.50 sec  
   Search  7.139 sec  
   Cart View  3.570 sec  
   Load  5.517 sec  

Top Issues

  • There were several instances of the app opening new connections when existing connections could have been reused, resulting in unnecessary overhead. Increasing the keep alive timeout value will help reduce load on your infrastructure and help save cost. This was the most glaring issue noticed in your app, and can be addressed immediately.
  • Cold Launch time to interact is 18.5 seconds on iOS. Reducing the cold launch time can enhance the app’s user experience.
  • Duplicate messages were detected within your app, with more than one request for the same resource occurring on 8 different hosts.

Launch Time

The Sephora App took 18.5 seconds to launch. There are no network calls visible during this launch, so the slowdown in launch must be from the client-side.

Connection Reuse

Connection CountTotal Connection Time (ss)Impact Time (ms) Impact Total (%) Host

This snapshot shows that there were 9 instances of the Sephora app creating new connections instead of reusing existing ones on the hosts listed.

HEADSPIN RECOMMENDATION: Consider organizing your connections into a few large buckets, versus many small buckets. Since every connection to your server keeps the device radio on, it’s crucial to minimize the connections that occur to preserve the battery consumption and cellular data used. Fixing this issue will also improve backend performance.

Duplicate Messages

This snapshot highlights duplicate resources that the app received. The demdex host saw 30 instances of the issue in the session. The Photorankapi host saw 14 instances of the issue.

HEADSPIN RECOMMENDATION: Consider caching your HTTP requests so that duplicates never reach the server. It is very unlikely for an app to need more than one copy of a resource.

How to Work With HeadSpin

HeadSpin Powers Flawless Mobile App Performance

HeadSpin’s state-of-the-art Digital Experience Intelligence Platform™ will empower your engineering teams to:

  • Execute automation tests on real carrier-enabled devices worldwide
  • Discover performance bottlenecks
  • Collect and visualize your performance data
  • Seamlessly integrate with your CI/CD workflow
  • Monitor every critical user flow of your mobile experience
  • Pinpoint issues that cause performance regressions and impact user experience earlier in your development cycle
Overarching Areas of Opportunities

  • Launch new features confidently by monitoring and analyzing root causes of performance issues throughout the development life cycle
  • Drive new user installs and user engagement with optimized performance
  • Forge user trust and safety, accelerating consumer services for critical user paths across your apps and website
  • Benchmark KPIs for mobile performance to understand how your user experience for your mobile app and website compares to your peers in the same industry
  • Support localized testing across 32,000+ devices and 160+ countries around the world, on real devices under real-world conditions
Expert Holistic Consultation and Strategy 

HeadSpin has the product and solutions expertise to help you perfect the digital experience for your customers! Our team hails from digital pioneers, such as Google and Facebook, and has already delivered enhanced mobile-centric experiences for a diverse set of Fortune 1000 clients. HeadSpin’s strategic insights can help you:

  • Drive new user acquisition, user engagement, and feature adoption
  • Deploy app security measures on iOS and Android
  • Build consistent performance standards and experiences across all your mobile apps and websites 

... insight from HeadSpin helps us prioritize issues so we could deliver a better user experience.

Maria Zhang, CTO, Tinder