Most of the tools mentioned so far in this thread (OneTab, Tab Wrangler, tree-style) either flatten your live-tabs-only into a list or auto-close them, and the common gap is that a tab you're keeping "for later" stops being visible the moment it's saved, so you never actually go back to it. What's worked better for me is a persistent tree where you can keep selected closed tabs in their original place: it leaves the strip to free RAM and space but stays visible in the same spot in your tree, nested or rearranged however you prefer. I build one called Pinako (so, biased), a tab manager that holds tabs and windows in an extremely flexible nested tree with everything saved independently of the browser session so a crash can't wipe it. Also has shareable archive-trees with rich-text, browser bookmarks in tree-form you can edit, nest or annotate, and trees for synced browsers and mobile devices so you can drag and drop links between them all.
For the HN crowd specifically: it's the only tab manager (to my knowledge) that fully speaks read/write MCP, so you can point Claude/Codex/Cursor etc. at your live tree and archives and have it reorganize, edit, or port all your data (research, notes, etc.) to other connected tools, instead of just answering questions about it. Runs on any Chromium browser.
Visual demo video can be seen here: https://chromewebstore.google.com/detail/pinako-ai-tab-sessi...