Security is and always will be one of the biggest topics in web development. Now that the mobile web becomes bigger and bigger it has become even more important because most users do not have any protection installed on there mobile devices.

Of course there is a very clear reason why people do not install anti virus apps on a mobile device, the threat is simply not yet big enough and there has not been any news report on mobile viruses or malware. This is something we, frontend developers, need to have in mind when developing web applications.

Working with backend systems

One of the methods to prevent people from submitting unwanted data is to validate the entered data. Most often there is little frontend validation and the backend will perform the rest of the validations. But is that enough? Most frontend validations are just checking whether or not a field is required. But when the user gets asked to enter some kind of pre-formatted code, such as a Dutch postal code (1234 AB), it is not only safer but also more userfriendly when a user can only enter four digits and two alphabetic characters.

This also works the other way around. When retrieving data from a backend system you should not want to have to care about a customer that sees strange things on a website Especially not when you are a trusted organisation. Therefore it might be a good idea to validate the data provided by the backend. This can be achieved by using the same validators that are used to validate the input data from the frontend.


Mobile and security are getting more important these days for frontend development. The examples given are of course just simple examples to illustrate how frontend can help in improving a site security.