wpautosave

“Wp-autosave” plugin is for automatically saving posts being written in the Classic Editor
Note: 
This plugin works as an additional module to the <a href="https://wordpress.org/plugins/classic-editor/" rel="ugc">Classic Editor</a> plugin by <a href="https://github.com/WordPress/classic-editor/" rel="nofollow ugc">WordPress Contributors</a> since <a href="https://wordpress.org/support/wordpress-version/version-5-0/" rel="ugc">WordPress version 5.0+</a>, because the original Classic Editor was replaced with a new editor – Gutenberg. 
So the original Classic Editor plugin is required to work with WP-Autosave plugin for all actual WordPress versions.
In case of older versions of WordPress (<5.0), the original Classic Editor plugin is not required because Classic Editor is used by default.
Major features of plugin: 
– Auto-save post to drafts at regular time intervals by multipart requests. (To check the functionality it’s enough to have the rights to create an entry in the wp-blog (you can test through a user-account) – you will see all requests through the developer tools or some other tools) 
– Intellectual immediately auto-save post to drafts when you change the text in the editor 
– You can attach a time-stamp to request through the settings of the plugin (appendix time of saving in the query) 
– You can set your auto-save interval 
– You can choose the type of saving – by time intervals or when content is changed

Wp-autosave

"Wp-autosave" plugin is for automatically saving posts being written in the Classic Editor

ska-dev

websevendev

By activating this plugin autosave feature in the Gutenberg editor will be disabled. Alternatively it also provides options in the editor to select a different autosave interval time than the default 60 seconds.
The block editor will still use local autosave that saves a copy of the edited post to your local storage and allows you to restore it if you happened to navigate away without saving. This plugin prevents the editor from making periodic requests to “*/autosaves” REST endpoint, which disables the “Update” button of the editor, typically at the exact moment you’re trying to click it.

Disable Gutenberg Autosave

Allows to control Gutenberg autosave interval or disable autosave completely.

Wp-autosave vs Disable Gutenberg Autosave