Index: src/wp-includes/general-template.php
===================================================================
--- src/wp-includes/general-template.php	(revision 53024)
+++ src/wp-includes/general-template.php	(working copy)
@@ -586,7 +586,7 @@
 		sprintf(
 			'<p class="login-username">
 				<label for="%1$s">%2$s</label>
-				<input type="text" name="log" id="%1$s" class="input" value="%3$s" size="20" />
+				<input type="text" name="log" id="%1$s" autocomplete="username" class="input" value="%3$s" size="20" />
 			</p>',
 			esc_attr( $args['id_username'] ),
 			esc_html( $args['label_username'] ),
@@ -595,7 +595,7 @@
 		sprintf(
 			'<p class="login-password">
 				<label for="%1$s">%2$s</label>
-				<input type="password" name="pwd" id="%1$s" class="input" value="" size="20" />
+				<input type="password" name="pwd" id="%1$s" autocomplete="current-password" class="input" value="" size="20" />
 			</p>',
 			esc_attr( $args['id_password'] ),
 			esc_html( $args['label_password'] )
Index: src/wp-login.php
===================================================================
--- src/wp-login.php	(revision 53024)
+++ src/wp-login.php	(working copy)
@@ -1060,11 +1060,11 @@
 		<form name="registerform" id="registerform" action="<?php echo esc_url( site_url( 'wp-login.php?action=register', 'login_post' ) ); ?>" method="post" novalidate="novalidate">
 			<p>
 				<label for="user_login"><?php _e( 'Username' ); ?></label>
-				<input type="text" name="user_login" id="user_login" class="input" value="<?php echo esc_attr( wp_unslash( $user_login ) ); ?>" size="20" autocapitalize="off" />
+				<input type="text" name="user_login" id="user_login" class="input" value="<?php echo esc_attr( wp_unslash( $user_login ) ); ?>" size="20" autocapitalize="off" autocomplete="username" />
 			</p>
 			<p>
 				<label for="user_email"><?php _e( 'Email' ); ?></label>
-				<input type="email" name="user_email" id="user_email" class="input" value="<?php echo esc_attr( wp_unslash( $user_email ) ); ?>" size="25" />
+				<input type="email" name="user_email" id="user_email" class="input" value="<?php echo esc_attr( wp_unslash( $user_email ) ); ?>" size="25" autocomplete="email" />
 			</p>
 			<?php
 
@@ -1387,13 +1387,13 @@
 		<form name="loginform" id="loginform" action="<?php echo esc_url( site_url( 'wp-login.php', 'login_post' ) ); ?>" method="post">
 			<p>
 				<label for="user_login"><?php _e( 'Username or Email Address' ); ?></label>
-				<input type="text" name="log" id="user_login"<?php echo $aria_describedby_error; ?> class="input" value="<?php echo esc_attr( $user_login ); ?>" size="20" autocapitalize="off" />
+				<input type="text" name="log" id="user_login"<?php echo $aria_describedby_error; ?> class="input" value="<?php echo esc_attr( $user_login ); ?>" size="20" autocapitalize="off" autocomplete="username" />
 			</p>
 
 			<div class="user-pass-wrap">
 				<label for="user_pass"><?php _e( 'Password' ); ?></label>
 				<div class="wp-pwd">
-					<input type="password" name="pwd" id="user_pass"<?php echo $aria_describedby_error; ?> class="input password-input" value="" size="20" />
+					<input type="password" name="pwd" id="user_pass"<?php echo $aria_describedby_error; ?> class="input password-input" value="" size="20" autocomplete="current-password" />
 					<button type="button" class="button button-secondary wp-hide-pw hide-if-no-js" data-toggle="0" aria-label="<?php esc_attr_e( 'Show password' ); ?>">
 						<span class="dashicons dashicons-visibility" aria-hidden="true"></span>
 					</button>
Index: src/wp-signup.php
===================================================================
--- src/wp-signup.php	(revision 53024)
+++ src/wp-signup.php	(working copy)
@@ -118,10 +118,10 @@
 	}
 
 	if ( ! is_subdomain_install() ) {
-		echo '<span class="prefix_address">' . $current_network->domain . $current_network->path . '</span><input name="blogname" type="text" id="blogname" value="' . esc_attr( $blogname ) . '" maxlength="60" /><br />';
+		echo '<span class="prefix_address">' . $current_network->domain . $current_network->path . '</span><input name="blogname" type="text" id="blogname" value="' . esc_attr( $blogname ) . '" maxlength="60" autocomplete="off" /><br />';
 	} else {
 		$site_domain = preg_replace( '|^www\.|', '', $current_network->domain );
-		echo '<input name="blogname" type="text" id="blogname" value="' . esc_attr( $blogname ) . '" maxlength="60" /><span class="suffix_address">.' . esc_html( $site_domain ) . '</span><br />';
+		echo '<input name="blogname" type="text" id="blogname" value="' . esc_attr( $blogname ) . '" maxlength="60" autocomplete="off" /><span class="suffix_address">.' . esc_html( $site_domain ) . '</span><br />';
 	}
 
 	if ( ! is_user_logged_in() ) {
@@ -149,7 +149,7 @@
 		<p class="error"><?php echo $errmsg; ?></p>
 		<?php
 	}
-	echo '<input name="blog_title" type="text" id="blog_title" value="' . esc_attr( $blog_title ) . '" />';
+	echo '<input name="blog_title" type="text" id="blog_title" value="' . esc_attr( $blog_title ) . '" autocomplete="off" />';
 	?>
 
 	<?php
@@ -260,7 +260,7 @@
 	if ( $errmsg ) {
 		echo '<p class="error">' . $errmsg . '</p>';
 	}
-	echo '<input name="user_name" type="text" id="user_name" value="' . esc_attr( $user_name ) . '" autocapitalize="none" autocorrect="off" maxlength="60" /><br />';
+	echo '<input name="user_name" type="text" id="user_name" value="' . esc_attr( $user_name ) . '" autocapitalize="none" autocorrect="off" maxlength="60" autocomplete="username" /><br />';
 	_e( '(Must be at least 4 characters, letters and numbers only.)' );
 	?>
 
@@ -271,7 +271,7 @@
 		?>
 		<p class="error"><?php echo $errmsg; ?></p>
 	<?php } ?>
-	<input name="user_email" type="email" id="user_email" value="<?php echo esc_attr( $user_email ); ?>" maxlength="200" /><br /><?php _e( 'We send your registration email to this address. (Double-check your email address before continuing.)' ); ?>
+	<input name="user_email" type="email" id="user_email" value="<?php echo esc_attr( $user_email ); ?>" maxlength="200" autocomplete="email" /><br /><?php _e( 'We send your registration email to this address. (Double-check your email address before continuing.)' ); ?>
 	<?php
 	$errmsg = $errors->get_error_message( 'generic' );
 	if ( $errmsg ) {