Press release

Bugsnag Announces Inaugural Application Stability Index Report, Reveals Mobile and Web Apps Fall Short of Stability “Five Nines”

Sponsored by Businesswire

Bugsnag Inc., an application stability management pioneer, today announced the results of its Application Stability Index: Are your Apps Healthy? The report analyzed the performance of approximately 2,500 top mobile and web applications (by session volume) within its customer base. The report reveals the median stability of mobile applications is 99.63%, while the median stability of web applications came in at 99.39%. These findings indicate almost four out of every 1000 customers could be having a completely broken experience with a mobile application. Similar to the “five nines” (99.999%) that infrastructure and operations teams use to measure uptime and availability, this benchmark will help development teams make decisions about when to build features versus fix bugs based on the application’s current stability.

“With more consumers using online apps, providing an error-free experience is of utmost importance to drive consumer engagement and retention,” said James Smith, CEO of Bugsnag. “To help engineering teams understand the stability and reliability of their apps, we’ve compiled data on the session-based stability of leading mobile and web applications across market segments to set a benchmark for app health. Engineering teams are always striving to innovate, and we’re dedicated to helping them achieve app stability excellence to deliver a better customer experience, drive loyalty and business growth.”

Measuring and Improving Application Stability for Mobile-First Engineering Organizations

Compared to the 99.999% industry target for most IT infrastructure groups, also known as “five nines,” a median stability of 99.63% presents a significant opportunity for engineering organizations to invest in measuring and improving application stability and customer experience.








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The report includes application data from several mobile development platforms, including Android, iOS, React Native, and Unity, as well as several front-end development platforms, including Angular, Backbone, Ember, React, and Vue. Key findings include:

  • Android and iOS native applications tend to have a higher median stability as specialized developers working on these applications have the expertise required to understand and address stability issues effectively.
  • Android applications tend to have a slightly lower median stability compared to iOS applications. As Android presents a much less constrained development environment due to increasing device fragmentation compared to iOS, it is inherently more difficult for Android development teams to test their applications.
  • React Native has a slightly lower median stability than the other mobile development platforms. Although it allows engineering teams to develop for iOS and Android together, expertise in these platforms is needed to effectively investigate and fix bugs in the native layers of the code.
  • Unity applications boast the highest median stability score. The isolated testing environment of Unity applications makes it less likely that a bug will crash the entire application.
  • Web applications have a lower median stability compared to mobile applications, indicating modern web development frameworks may provide more resources to manage errors.
  • There is correlation between size of the engineering team and median stability scores. The smaller the engineering team, the lower the median stability. This holds true in teams up to 50 engineers as achieving product-market fit is more important than app stability. However, large teams of 100+ engineers working on more mature applications experience challenges such as legacy code, compounding technical debt and complexity of team structure that result in declining stability scores.

“Although stability is commonly a KPI owned by engineering organizations, it has a significant impact on overall business performance and growth,” said Smith. “Engineering organizations can no longer separate business metrics from the stability of their applications — they must standardize error monitoring and stability solutions across the stack and across multiple teams.”

Bugsnag is meeting this challenge head on and enabling teams to measure and improve app stability, so organizations can increase competitive advantage and drive business growth.

About the Bugsnag Stability Index Report:

The Bugsnag Stability Index Report is based on actual customer sessions and 30-day stability assessments patterns that were analyzed and scored by the Bugsnag Application Stability Management platform in 2020. For more information, please visit:

About Bugsnag

Bugsnag is a pioneer in application stability management. We make error monitoring actionable and help enterprises and small businesses stabilize, prioritize and fix bugs. As a full stack solution, we are recognized for our best-in-class support for mobile applications. Bugsnag empowers software development, client observability and release management teams to make data-driven decisions on when to build features versus fix bugs.

Organizations experience significant ROI due to faster innovation led by developer efficiencies and improved customer experiences. We process over 1 billion crash reports every day from applications worldwide and more than 5,000 industry leading brands including Airbnb, Slack, Pinterest, Lyft, Yelp and Pandora use Bugsnag as their daily dashboard. Based in San Francisco, Bugsnag is backed by GV (Google Ventures), Benchmark Capital and Matrix Partners. For more information, visit