There are many inbuilt functions for WordPress posts like the AutoSave, Post Revisions, etc. One can easily tweak them without much coding knowledge. The following changes have to be made in the wp-config.php file.
Modify AutoSave Interval
When editing a post, WordPress uses Ajax to auto-save revisions to the post as you edit. You may want to increase this setting for longer delays in between auto-saves, or decrease the setting to make sure you never lose changes. The default is 60 seconds.
define( 'AUTOSAVE_INTERVAL', 160 ); // Seconds
Post Revisions
WordPress post revisions, by default, will save copies of each edit made to a post or page, allowing the possibility of reverting to a previous version of that post or page. The saving of revisions can be disabled, or a maximum number of revisions per post or page can be specified.
Also read :
Disable Post Revisions
If you do not set this value, WordPress defaults WP_POST_REVISIONS to true(enable post revisions). If you want to disable the awesome revisions feature, use this setting:
define( 'WP_POST_REVISIONS', false );
Note: Some users could not get this to function until moving the command to the first line under the initial block comment in config.php.
Specify the Maximum Number of Post Revisions
If you want to specify a maximum number of revisions, change false to an integer/number (for example 2 or 4).
define( 'WP_POST_REVISIONS', 3 );