What are Prefillers and How Do They Work?

A prefiller is a script or a piece of code that fills in form fields with predefined values before the user has a chance to interact with the form. The purpose of a prefiler is to automate the process of filling out forms, which can be useful in various scenarios, such as:

1. Testing: Prefillers can be used to test forms and ensure that they are functioning correctly. By automatically filling in form fields with specific values, developers can simulate user interactions and verify that the form behaves as expected.
2. Data population: Prefillers can be used to populate forms with data from a database or another source. This can be useful when you have a large amount of data that needs to be entered into a form, but you don't want to manually enter it all.
3. Automation: Prefillers can be used to automate the process of filling out forms for repetitive tasks. For example, if you have a form that you need to fill out every day, a prefiler can save you time by automatically filling in the form fields with the same values each day.

There are different types of prefillers available, including:

1. JavaScript-based prefillers: These prefillers use JavaScript to fill in form fields. They are often used for testing and development purposes, as they can be easily integrated into web pages.
2. Browser extensions: Some browser extensions, such as uBlock Origin, come with built-in prefillers that can automatically fill in form fields.
3. Third-party prefillers: There are also third-party prefillers available, such as Form Auto Filler and Form Filler, which can be used to automate the process of filling out forms.

It's important to note that prefillers can be useful tools, but they can also be a security risk if not used properly. If you use a prefiler to fill in form fields with sensitive information, make sure that the prefiler is trustworthy and that the information being filled in is secure.