autofilled

Autofilled refers to the automatic filling of form fields by software, typically using data previously entered by the user or provided by a trusted source. It is common in web browsers, mobile apps, and operating systems to speed data entry and reduce repetition. Autofilled data can populate text fields, select options, and, for credentials, login forms, depending on the data available and the application's design.

How it works: Autofill relies on stored data such as contact information, addresses, payment details, and usernames. When a user focuses a form field, the autofill engine matches the field type and suggests or fills the most appropriate value. Users can review, edit, or delete saved data and configure where autofill is allowed.

In practice, autofill is implemented in browsers (Chrome, Firefox, Safari), mobile platforms (iOS, Android), and through password managers. Web developers can influence behavior by giving meaningful field names and using the HTML autocomplete attribute, and by implementing accessible forms that do not rely solely on autofill.

Privacy and security: Autofill can reveal sensitive information if devices are shared or compromised, or if a user is tricked by phishing sites. Best practices include enabling autofill only on trusted devices, using strong authentication for password managers, and restricting autofill for sensitive fields. Developers should respect user preferences and use correct autocomplete values to minimize risk.

Limitations: Autofill may fail on dynamic or complex forms, may misfill if stored data is outdated, and can cause errors if not clearly labeled. It should be tested for accessibility so that assistive technologies announce filled values appropriately.