Abstract-This paper introduces the Solar Lab Notebook (SLN), an electronic lab notebook for improving the process of recording and sharing solar related digital information in an organized manner. SLN is a pure web-based application (available online: http://umbra.nascom.nasa.gov/sln) that runs client-side only, employing a clean and very friendly graphical user interface design, and thus providing a true cross-platform user experience. Furthermore, SLN leverages unique technologies offered by modern web browsers, such as the FileReader API, the Blob interface and Local Storage mechanism; it is coded entirely using HTML5, CSS3, and JavaScript, and powered by the extremely well documented XML file format. For highsecurity labs, it can be utilized as an ultra-portable and secure digital notebook solution, since it is functionally self-contained, and does not require any server-side process running on either the local or a remote system. Finally, the W3C XML Schema language is used to define a list of rules, namely a data standard, that an SLN file must conform to in order to be valid. In this way, developers are able to implement their own validation functions in their projects, or use one of the freely available tools to check if a data file is properly structured. Similarly, scientific groups at different labs can easily share information, being confident about the integrity of the exchanged data.