In the relatively short time of its existence, the Internet has been rapidly evolving. In proportion to its development, web technologies have developed, too. All of this has resulted in a huge amount of data which continues to grow. Therefore, security of data or information has become a very important issue. This graduated thesis presents in details the process of creating web applications that enable secure password storage. The user can create an account or log in into the application if he has already created an account. After logging in, the user has the option to save passwords and password-related data such as the name and url of the page to which the password applies. Also, user can update, search or delete already saved data. The web application has a chrome extension that allows the user to find a saved password for a given page based on the active chrome tab. In the preparation of this thesis, the most modern web technologies were used, such as Vue.js, Node.js and MongoDb, as well as npm packages such as bcrypt and crypto-js which enabled easy implementation of cryptographic algorithms. The user interface was created using the Vue.js framework, which is one of the increasingly popular and growing frameworks for web user interface development. It enables quick and easy integration with Node.js technology, which is widely used today to create the server part of web applications. The server side is easily and quickly created using the express npm package. MongoDb was used to create the database, but also Mongoose ORM to make it easier to translate documents from the MongoDb database to objects within the program. The data stored in the database is encrypted using the AES algorithm. The key that uses the AES algorithm was created with the PBDKF2 function, which made it possible to achieve a high degree of security.