In general, Link Whisper Premium contains all of the functionality of Link Whisper Free, but the features are more advanced and the user has more control over them. Also, Link Whisper Premium has a number of features that Link Whisper Free does not have.
The prominent differences between the plugins break down like this.
|Link Whisper Free
|Link Whisper Premium
|Displays the Inbound and Outbound links for each post.
|Displays the Inbound and Outbound links for each post and allows you to delete any links you don’t want with a single click.
|Has a single report for displaying link stats.
|Has a Dashboard for displaying general stats and reports for showing link stats, domain linking stats, link click stats, and a broken links report.
|Creates Outbound suggested links that have to be manually inserted.
|Creates Outbound and Inbound suggested links that are automatically inserted into posts once you approve them.
|Has Link Whisper suggestion algorithm to generate suggestions.
|Has Link Whisper suggestion algorithm which can be enhanced with GSC keyword data, Yoast/Rank Math keywords, custom keywords, and multiple content ignoring/emphasizing settings.
|Has no automatic linking option.
|Has autolinking feature that allows you to define keywords and destination URLs which will be automatically inserted into all past and future posts.
|Has no URL editing abilities.
|Has a dedicated URL Changer that can update any link in the post types selected for processing. Also has specific-link URL editing from the Domain and Error reports.
|Works on multiple page builders*, needs links to be manually inserted in the builder content.
|Works on multiple page builders*, will insert links in the page builder content when you click the “Insert Links” button.
|Able to select public post types for processing.
|Able to select public and non-public post types for processing.
|Able to select standard WordPress category and tag archive pages for suggestion processing.
|Able to select all registered category and tag archive pages for suggestion processing.
|Doesn’t check for broken links.
|Automatically checks for broken links, and allows you to delete or update the links.
|Doesn’t track link clicks.
|Does track link clicks and displays the results in a report page. Can display the click stats for specific posts or links over a user-specified time length.
|Free to install and use from WordPress.org.
|A year of service and updates for a single site is only $77 (~$6.41 a month). The pricing options are available here.
*The Outbound suggestions for page builder content is generated in the post edit screen, not in the page builder itself. You can get a free trial of the premium version for a limited time.