Two-dimensional gel electrophoresis can retrieve information regarding thousands of different proteins from a crude protein sample. One of the major challenges in field of proteomics is to extract maximum information from 2D gels. In this study, we developed a web server for the analysis and comparison of 2D gels, which consists of three major modules. The first module allows the analysis of gels on the basis of molecular weight and pH. This module assists in calculating molecular weight and pH of a protein by clicking on corresponding spot at 2D gel image. The second module allows the comparison of two gels and presents the result as a superimposed image where spots/proteins on two gels can be examined. The useful feature of this module is that it allows the comparison of whole gel images or user specified areas or spots of gels. Besides this, it also allows zooming and other image transformations such as brightness and contract enhancement. The third module is an interface to the database of 2-D gel images maintained locally. The database consists of information about more than 3500 well annotated 2-D gel images obtained from public databases and literature. The server allows searching of gels from the database by keyword. Web server AC2Dgel is available for public from http://www1.imtech.res.in/raghava/ac2dgel/.