This article describes how to change the auto-save interval in WordPress.
The WordPress auto-save feature periodically saves a draft of your post as you edit it. By default, WordPress saves a draft every 60 seconds.
However, there are situations where you may want to change this interval. For example, if you have a slow internet connection, you may want to increase the interval so your browser does not “hang” as frequently when WordPress saves a draft. Alternatively, if you want to minimize the chances of losing edits to a post, you can decrease the auto-save interval so WordPress saves them more frequently.
To change the length of time that WordPress waits between automatically saving drafts, follow these steps:
define( 'AUTOSAVE_INTERVAL', X );
Make sure the auto-save line above comes before the following line in the wp-config.php file, or else the setting has no effect:
require_once(ABSPATH . 'wp-settings.php');