Circadian oscillations, over approximately 24-h, are very important and among the most studied physiological oscillations. To evaluate the presence and significance of 24-h oscillations, physiological time distributed data are often set to a cosinor model using a wide range of irregularly updated (very often outdated) native apps which have problem with modern operating systems. Therefore, for users not familiar with MATLAB, R or other programming languages, we created Cosinor.Online application. The application is running in modern web browsers and is hosted on remote servers running 24/7.

Cosinor.Online, cosinor on the web:
More about the application in the preprint on BioRxiv, doi: .
Reference: Molcan, L. (2019). Time distributed data analysis by Cosinor. Online application. bioRxiv, 805960.

Input data

Period Length (hours):


CoW example


  • Period length (hours): decimal form. Examples: 24, 24.0, 23.6, 12.56 etc.
  • Column one: Time, decimal form. Transform 20:30 to 20.5 etc. If you are not sure how, please, visit this page.
  • Column two: Values, decimal form. Examples: 2.10, 5, 5.8, 100.2 etc.