YouTube Sub Manager od Shadeov

YouTube Sub Manager makes the Channels page easier to use. You stay where you already browse subscriptions, see what’s new, tidy the list, and move channels to another account.

• Up to eight recent videos under each channel
• Three list layouts: Original, Compact, and Table
• Select channels, unsubscribe in bulk, and export the ones you picked
• Export to JSON, import from JSON or OPML with a preview
• Settings and files stay on your device; requests go only to YouTube

Install the extension, sign in to YouTube, and open the Channels page.
Export, Import, and Select appear beside the filters. The interface follows your browser language.