Where the words added with the User Dictionary are stored?

Depending on the type of product used, the initial storage for words will be different.

• SpellCheckAsYouType (SCAYT): By default, all words added using SCAYT User Dictionary functionality will go to the browser's local storage. Thus, all the words will be stored on end user’s side and will be available from a particular browser. 
• WProofreader: By default, all words added using WProofreader User Dictionary functionality will go to the browser's local storage. Thus, all the words will be stored on end user’s side and will be available from a particular browser. 
• WebSpellChecker Dialog (WSC): The words added using WSC User Dictionary functionality will be saved in the browser's cookies, as well on the end user’s side.

In order to have access to a personal dictionary and be able to use it from different browsers and machines (or devices) while working with the system, an end user has to create a dictionary from Dictionary tab of SCAYT or the Options section of WSC. This dictionary will be saved and stored on the Server. In the case with the Cloud version of the WebSpellChecker Services, such a dictionary will be stored on the WebSpellChecker Servers. For the Server version — on the client’s server where the WebSpellChecker application is installed and running. 

As soon as the end-user decides to create a personal user dictionary on the server, all the words from cookies (WSC) or local storage (SCAYT) will be moved to the dictionary on the server accordingly.