Last updated: 2026-05-14
Lostless is a Chrome extension that adds bookmarks, inline notes, and sub-thread navigation to Claude.ai. This page explains exactly what data Lostless touches, what it does with it, and what it never does.
The extension stores the following on your device only, in chrome.storage.local, scoped to your browser profile:
This data never leaves your device.
Nothing, with one exception. In normal use the extension makes no outbound network calls — all your bookmarks, notes, and threads stay on your device.
If you opt in to release-notes email on the welcome page: your email address is sent to a Lostless intake endpoint and stored for the sole purpose of notifying you when paid features launch. We do not sell, share, or use it for any other purpose.
To anchor bookmarks and notes to specific paragraphs, the extension reads the DOM of claude.ai pages while you have them open. It only stores text from a paragraph if you explicitly bookmark or note it. It does not transmit page content anywhere.
All local data persists until you uninstall the extension or clear browser data. Uninstalling Lostless removes the extension's local storage entirely.
If you opted in to email: reply to any release-notes email with "remove" or email [email protected] and we'll delete your address.
The extension requests these Chrome permissions:
storage — to keep your bookmarks/notes locally.activeTab — to inject the bookmarking UI into the active Claude.ai tab.host_permissions: claude.ai/* — to run on Claude.ai pages.If we ever change this policy, we'll update the date at the top and announce it via the welcome page on the next extension update. We will never reduce your privacy without an explicit opt-in.
Questions, deletion requests, or concerns: [email protected].