Recent discovery of thousands of small and large noncoding RNAs, in parallel to technical improvements enabling scientists to study the transcriptome in much higher depth, has resulted in massive data generation. This burst of information prompts the development of easily accessible resources for storage, retrieval and analysis of raw and processed data, and hundreds of Web-based tools dedicated to these tasks have been made available. However, the increasing number and diversity of bioinformatics tools, each covering a specific and specialized area, as well as their redundancies, represent potential sources of complication for end users. To overcome these issues, we are introducing an easy-to-follow classification of microRNA (miRNA)-related bioinformatics tools for biologists interested in studying this important class of small noncoding RNAs. We also developed our miRNA database miRNA algorithmic network database (miRandb) that is a meta-database, which presents a survey ofxe2x80x89>xe2x80x89180 Web-based miRNA databases. These include miRNA sequence, discovery, target prediction, target validation, expression and regulation, functions and their roles in diseases, interactions in cellular pathways and networks and deep sequencing. miRandb recapitulates the diverse possibilities and facilitates that access to the different categories of miRNA resources. Researchers can easily select the category of miRNA information and desired organism, in result eligible databases with their features are presented. This database introducing an easy-to-follow classification of available resources that can facilitate selection of appropriate resources for miRNA-related bioinformatics tools. Finally, we described current shortages and future necessities that assist researchers to use these tools easily. Our database is accessible at http://mirandb.ir.