This page shows some statistics for the Carat community. All the numbers shown here are across the entire Carat community and may differ from suggestions and numbers displayed by Carat for any individual user.

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These statistics were generated from data gathered by the Carat project. All numbers are estimates generated by a computer program.

Currently, this page works best with recent versions of Chrome.

General statistics

These statistics use two terms, energy-intensive applications (or Hogs) and energy anomalies (or Bugs). Energy-intensive applications use more of your battery than average applications. Typical energy-intensive applications include Internet radio, watching movies, voice communications, and 3D games. Energy anomalies are applications that behave normally for most users, but use more than average energy for a particular user or users. These can be caused by user settings, application configurations, or programming errors in the application.

Out of installed applications, % are energy-intensive (Hogs in the Carat App) and % are energy anomalies (Bugs).

Out of installed Android applications, % are energy-intensive and % are energy anomalies.

Out of installed iOS applications, % are energy-intensive and % are energy anomalies.

Out of users, % have at least a single energy anomaly.

Popular Device Models



      Operating System Versions and Device Models

      The below chart displays how users are distributed between platforms, operating system versions and device models. Click a segment to zoom in. Click in the center to zoom out.

      Top 200 Energy-Intensive Applications

      The bubble chart below shows the evolution of the top 200 most energy-intensive applications on Android or iOS. Click your platform, then click Play. Area of the circle indicates the number of users of the application and the color indicates how much battery life would be gained if a user would stop using that application. Note that color and size are not comparable between platforms.

      Users: Measurements: Stop using to gain: min
      Play »

      CaratThe Carat Team

      Carat is brought to you by the Carat team at the University of Helsinki, Department of Computer Science. Carat was started at the Algorithms, Machines, and People Laboratory (AMP Lab) in the EECS Department at UC Berkeley, in collaboration with the Department of Computer Science at the University of Helsinki. The project combines expertise from multiple areas, such as mobile application development, statistical data analysis, and mobile energy awareness. Carat is currently maintained by the University of Helsinki. The Carat team is introduced below.

      Current Team Members

      Eemil Eemil Lagerspetz is a postdoctoral researcher at the University of Helsinki. He completed his PhD at the University of Helsinki in 2014. His research interests include large-scale data analysis (Big Data), mobile data management, data communications, and energy efficiency. He is currently the main maintainer for Carat. Contact him at

      Ella Ella Peltonen is a graduate student at the University of Helsinki. Her research interests include distributed machine learning and data mining methods for large and ambiguous data sets. In the Carat project, she focuses on detecting energy anomalies from Carat's rich context factor data, and turning them into actionable recommendations. She received a MSc and a BSc in Computer Science from the University of Helsinki. Contact her at

      Jonatan Jonatan Hamberg is a research assistant at the University of Helsinki. He is maintaining the Carat backend and developing iOS and Android applications. Contact him at

      Paula Paula Lehtola is a research assistant at the University of Helsinki and the main author of the Statistics page. She is currently working with her Master thesis on application recommendations. Contact her at

      Sasu Sasu Tarkoma received his M.Sc. and Ph.D. degrees in Computer Science from the University of Helsinki, Department of Computer Science. He is full professor at University of Helsinki, Department of Computer Science and Head of the networking and services specialization line. He has managed and participated in national and international research projects at the University of Helsinki, Aalto University, and Helsinki Institute for Information Technology (HIIT). He has worked in the IT industry as a consultant and chief system architect as well as principal researcher and laboratory expert at Nokia Research Center. His interests include mobile computing, Internet technologies, and middleware. He can be reached at

      Past Team Members

      MikaMika Viinamäki is a research assistant at the University of Helsinki and the main author of the Statistis page. He has also contributed to the Carat analysis engine.

      Adam Adam Oliner is a postdoctoral scholar in EECS at UC Berkeley, working with Ion Stoica and the AMP Lab. He recently finished a PhD in computer science at Stanford University, advised by Alex Aiken, where he was a DOE HPCS Fellow and an Honorary Stanford Graduate Fellow. Adam received a MEng in electrical engineering and computer science from MIT, where he also completed undergraduate degrees in computer science and mathematics. Adam's research focuses on understanding complex systems.

      Anand Anand Iyer is a graduate student in the Computer Science division at the University of California, Berkeley. He is currently interested in the synergy between mobile systems and cloud computing. He received a Masters degree in Computer Science from The University of Texas at Austin.

      Ion Ion Stoica is a Professor in EECS at University of California, Berkeley. He received his M.S. in Computer Science and Control Engineering from Polytechnic University Bucharest, 1989, and a Ph.D. in Electrical and Computer Engineering from Carnegie Mellon University, 2000. He joined the faculty of EECS in 2000. His research areas include Operating Systems & Networking (OSNT), Security (SEC), Networking and distributed computer systems, Quality of Service (Q of S) and resources management, modeling and performance analysis. Stoica is the recipient of the 2007 CoNEXT Rising Star Award, a Sloan Foundation Fellowship (2003), a Presidential Early Career Award for Scientists & Engineers (PECASE) (2002), and the ACM doctoral dissertation award (2001). He also serves as a CTO at Conviva, which he co-founded in 2006.