Defenestrator by pd

Refenestrator is a lightweight browser extension that saves and restores window-level tab sessions to timestamped JSON files. It focuses on preserving window context (one "session" = one browser window), making it easy to snapshot a window, inspect the saved session, and restore it later — even across devices.

Base principle: Refenestrator is file-based to allow flexible usage and control. It is suitable for scripted workflows and passing around sessions without the usual overhead of bookmarks and browser synchronisation.

Its auto save option creates a low-dependency backup of tabs/URLs by window.