Editing Autocomplete (section)

=== In web browsers ===
[[File:Autocomplete Mozilla Firefox 23 - Wikipedia de search.png|thumb|Autocomplete of the search box in [[Mozilla Firefox]]]]
In [[web browser]]s, autocomplete is done in the address bar (using items from the browser's history) and in text boxes on frequently used pages, such as a [[search engine]]'s search box. Autocomplete for web addresses is particularly convenient because the full addresses are often long and difficult to type correctly. 

==== In web forms ====
Autocompletion or "autofill" is frequently found in web browsers, used to fill in [[Form (HTML)|web forms]] automatically. When a user inputs data into a form and subsequently submits it, the web browser will often save the form's contents by default.{{Citation needed|date=April 2022}} 

This feature is commonly used to fill in login credentials. However, when a password field is detected, the web browser will typically ask the user for explicit confirmation before saving the password in its password store, often secured with a built-in [[password manager]] to allow the use of a "master password" before credentials can be autofilled.<ref>{{Cite web|url=https://support.mozilla.org/en-US/kb/password-manager-remember-delete-edit-logins|title=Password Manager - Remember, delete and edit logins and passwords in Firefox|website=Firefox Support}}</ref>

Most of the time, such as in Internet Explorer and Google Toolbar, the entries depend on the form field's name, so as to not enter street names in a last name field or vice versa. For this use, proposed names for such form fields, in earlier HTML 5 specifications this RFC is no longer referenced, thus leaving the selection of names up to each browser's implementation.

Certain web browsers such as [[Opera (web browser)|Opera]] automatically autofill [[credit card]] information and [[street address|addresses]].<ref>{{Cite web|url=https://cloudfour.com/thinks/autofill-what-web-devs-should-know-but-dont/|title=Autofill: What web devs should know, but don't|website=Cloud Four|date=19 May 2016 }}</ref>

An individual webpage may enable or disable browser autofill by default. This is done in [[HTML]] with the <code>autocomplete</code> attribute in a <code>&lt;form&gt;</code> element or its corresponding form elements.

<syntaxhighlight lang="html">
<!-- Autocomplete turned on by default -->
<form autocomplete="on">

  <!-- This form element has autocomplete turned on -->
  <input name="username" autocomplete="on">

  <!-- While this one inherits its parent form's value -->
  <input name="password" type="password">
</form>
</syntaxhighlight>

It has been shown that the autofill feature of modern browsers can be exploited in a [[phishing]] attack with the use of hidden form fields, which allows [[personal information]] such as the user's phone number to be collected.<ref>{{Cite web|url=https://www.bleepingcomputer.com/news/security/browser-autofill-profiles-can-be-abused-for-phishing-attacks/|title=Browser Autofill Profiles Can Be Abused for Phishing Attacks|website=Bleeping Computer}}</ref>