Scripting languages require the use of high-level library functions to implement efficient image processing; thus, real-time image blur in web-based applications is a challenging task unless specific library functions are available for this purpose. We present a pyramid blur algorithm, which can be implemented using a subimage copy function, and evaluate its performance with various web browsers in comparison to an infinite impulse response filter. While this pyramid algorithm was first proposed for GPU-based image processing, its applicability to web-based applications indicates that some GPU techniques are of more general interest than previously assumed.