JavaScript is a programming language used in web development to make interactive websites. A client-side language, JavaScript code is processed by the web browser and not the webserver. It can be placed anywhere within the HTML of a webpage. JavaScript is supported by all web browsers and allows web pages to perform interactive functions such as video, dynamic content, GIFs, etc.
If you want to embed a customizable signup form in your website, you can generate the required HTML and JavaScript in Campaign Monitor, and use our form builder to style it—or style it yourself using CSS. Note that this type of subscribe form requires some knowledge of HTML and CSS.
In terms of email, there are several conflicts with inserting JavaScript into your email campaigns. The foremost conflict is that most inbox providers are already using JavaScript to render the inbox’s interface, and any JavaScript in your email is likely to be blocked by those providers so that their own code and experience is protected.
When it comes to using JavaScript in email, the costs far outweigh the benefits. Even though you might get your JavaScript to run, there are better, more surefire ways to code your advanced elements using HTML and CSS. You can read more about advanced email coding (including use of Java in emails) in this guide.