No. Minified JavaScript, while not an "executable" in the software engineering sense of the word, is difficult for humans to read, edit, and modify. As such, it is not "the preferred form for modification" and so it is not Source Code as defined by the license. Therefore, minified JavaScript is the Executable form, and the responsibilities set out in the license for distribution of the Executable form should be met when you distribute minified MPL-licensed JavaScript. This means, among other things, that you do not need to, and probably should not preserve the MPL boilerplate (which begins "This Source Code Form...") when minifying JavaScript. However, you do need to comply with section 3.2(a) by informing the recipients of the minified source how they can obtain a copy of the source code. How exactly you do this will depend on how they can obtain that copy, but one way would be to include a comment with a link to the source code in either the page which uses the JavaScript or in the JavaScript file itself. Note that treating minified JavaScript as an executable increases distributor flexibility by allowing MPL-licensed code to be combined into a single file with non-MPL JavaScript source code without requiring the non-MPL code to be distributed under the terms of the MPL.