As different as the use cases for online forms are, so are the requirements for the online form. A few tricks will help you to integrate the desired functions into the web form.
File types for file upload
Files can also be uploaded with an online form. However, in most cases, you do not want to allow all file types, but only certain files, such as image files.
The signature field in the online form.
It is also possible to insert a signature field into an HTML form. This can be used to more or less confirm a certain fact. The signature is made on the desktop PC using the mouse pointer. On devices with touch operation, the signature is made using a suitable pen or finger.
Autocomplete the city data
In a web form with the data fields postcode (postcode) and city, you can automatically complete the city entry when entering the postcode. This saves the user typing work and also avoids misspellings.
Border color and style of a form field
CSS can be used to adapt the border color and style of a form field to your own design requirements.
Passing values to an HTML form
This article describes how to pass data or values when calling up a web form so that, for example, form fields can be pre-filled with these values.
Form field frames with rounded corners
Online forms look chic and modern if the frame of the form fields is displayed with rounded corners. This looks especially good on mobile devices. But remember: design is subject to fashion; at some point, square edges could also be fashionable again.