CUSTODIAN
FAQ
Questions worth actually answering.
No "what is a cookie." These are the questions people ask once they already understand what Custodian does.
Does whitelisting a site undo permissions it already reset?
Yes. Chrome only lets an extension clear its permission overrides for an entire permission type at once, not one site at a time. Custodian works around that by tracking exactly which sites it's touched per permission type, so whitelisting a site clears the type-wide override and immediately writes every other affected site's protection back. The site you whitelisted is now free to re-prompt normally, and everything else is unaffected. Details are on the How it works page.
What happens if Chrome kills the extension mid-countdown?
Manifest V3 background service workers can be suspended at any time, including mid-countdown. Custodian writes the pending countdown to local storage as soon as it starts, so if the worker is later woken up, it can pick up where it left off, or restart the grace period if it can't tell exactly how much time already passed. Either way, nothing gets cleared without a grace period actually completing. Worst case is an extra few seconds of delay, not a skipped check.
Does the network isolation feature block WebRTC?
No. "Isolate this tab" blocks navigations, fetch and XHR requests, scripts, images, and WebSockets for that tab, using declarativeNetRequest scoped to its tab ID. WebRTC negotiates its own peer-to-peer connection outside that request pipeline, so it isn't covered. This isn't full air-gapping, and it's stated as a limit wherever the feature comes up, not buried in fine print.
Why does Custodian need access to every site instead of just the ones I use it on?
Because Custodian doesn't know in advance which site you'll close a tab for next. The broad host permission is what lets it watch tab-close events and clear storage on any site, rather than a fixed list you'd have to maintain yourself. The permission is wide, but the behavior on any given site is narrow and consistent: nothing is read or sent anywhere, only cleared, and only once that site's last tab closes.
What exactly counts as "the last tab" for a site?
Custodian tracks tabs by origin: scheme, host, and port together. Different subdomains count as different sites, and the same host on a different port counts separately too, which matches the boundary Chrome itself uses for cookies and storage. If you have tabs open for both app.example.com and example.com, closing the last tab for one doesn't affect the other.
Does Shield Mode also honor the grace period?
Yes. Shield Mode changes which sites get cleared by default, not the mechanism. The same cancelable grace period runs before Custodian acts on any site that isn't marked clean.
What happens to greylisted sites when they expire?
Nothing happens immediately. Expiry just removes the site's temporary protected status. Custodian only ever acts when a site's last tab closes, so an expired greylist entry simply means the next time you close that site's last tab, it's treated like any other site instead of being skipped.
Can Custodian tell whitelisted sites apart from ones I just haven't visited?
Yes. The whitelist is an explicit list you control. A site you've simply never visited isn't on it, and if you do visit it later, it gets Custodian's normal handling like any other site, not the whitelist's never-touch treatment.
Does clearing data disconnect me from a site I'm still using in another window?
No. Custodian tracks tabs for an origin across all windows, not per window. If you still have a tab open for a site anywhere, in any window, that site's last tab hasn't closed, and nothing is cleared.
Is there a way to sync settings across devices?
No, and that's deliberate rather than an oversight. Custodian has no account system and no server to sync through, so your whitelist, greylist, and settings stay local to the Chrome profile you set them up in. If you want the same setup on another machine, you'd configure it there separately.