autofill

to automatically fill (the fields in a digital document, especially a web page) from data previously saved in the browser, such as a user’s name and address or credit card information: Completing forms is so much easier when the computer autofills them for you.: Compare auto-populate.

sometimes used interchangeably with autocomplete (def. 1).

a feature of a web browser that automatically fills the fields in a digital document with previously saved user data: If you supply the information, your browser will be able to use autofill at the checkout screen for most online retailers.