Simmer privacy policy
Last updated 3 November 2026
Short version: Simmer keeps everything in your browser. There is no account, no analytics, no ads and no Simmer server. Nothing about your tabs or bookmarks leaves your computer unless you switch on a feature that needs it, and each of those is listed below.
What Simmer reads
To group, sleep, archive and bookmark tabs, Simmer reads, on your computer:
- the address, title and group of your open tabs, and when each was last used;
- your bookmark folders and bookmarks, to file tabs into them and suggest tidy-ups;
- your recently closed tabs, when you open that list in the side panel;
- your Chrome Reading List, only when you add tabs to it from Simmer.
Only if you allow it, in a separate Chrome permission prompt:
- Browsing history, to show when you last opened a bookmark in Bookmarks → Clean up;
- Page descriptions (the short summary a page gives about itself), to file a tab into a better folder.
To work out what you're in the middle of, Simmer notes which tab opened which, and compares tab titles with a small model inside the extension. Both happen on your computer and nothing is sent anywhere. You can turn each off in Settings. If you paste or drop an export from another tab manager, its links go into your archive and stay on this computer.
Where it is kept
Everything Simmer saves (your archive of closed tabs, notes, workspaces, snoozed tabs, the activity list and what it has learned) is stored with Chrome's extension storage on this computer. Your settings, such as grouping rules, are saved with Chrome's own sync so they follow your Chrome profile, exactly like any other extension's settings. A Claude API key, if you add one, stays on this computer and is never synced.
It also keeps snapshots of your open tabs (addresses, titles and groups) on this computer, so Put things back can return to an earlier point. These never leave your computer.
If you turn on automatic backups, which ask Chrome's permission once, Simmer writes a copy of this data to Downloads/Simmer on your computer. It doesn't include a Claude API key. Those files are yours, and uninstalling Simmer leaves them in place.
Simmer makes real Chrome bookmarks. They are yours: uninstalling Simmer removes its own stored data but leaves your bookmarks where they are.
What can leave your computer, and only when you switch it on
| Feature (off until you turn it on) | What is sent, and where |
|---|---|
| Claude features: group by topic, pick folders, one-line summaries, Ask, suggested bookmark structure | Tab and page titles, site names, page descriptions and bookmark folder names are sent to
Anthropic's Claude API (api.anthropic.com) with your own API key. Full
addresses are not sent. Anthropic's own terms and privacy policy apply to that request. Tab
Butler prefers Chrome's built-in on-device model when your computer has it; that one sends nothing. |
| Check bookmark links | Simmer visits each bookmarked address, from your browser, to see whether the page still exists. |
| Read pages | Nothing is sent. Simmer reads the description of a page you already have open, on your computer. |
| Agent access (Settings → Agent access) | Lets an AI app installed on your own computer (such as Claude Code) list and organize tabs through a local connection you install. Nothing goes over the network from Simmer. |
Site icons in Simmer's pages come from Chrome's built-in favicon cache.
What Simmer never does
- It has no server and collects no analytics, crash reports or usage data.
- It does not sell, share or transfer your data to anyone.
- It does not use your data for advertising, credit decisions or anything other than organizing your tabs and bookmarks.
- It does not load or run code from the internet. The model is part of the package.
Removing your data
Settings → Data exports everything Simmer keeps, and archived tabs can be removed from the Archive page. Uninstalling Simmer deletes all of its stored data from this computer, except backup files in your Downloads folder, which you can delete yourself; settings saved with Chrome sync are removed by Chrome.
Changes and contact
If this policy changes, the date above changes with it, and a new version of Simmer will say what changed. Questions: addobari31@gmail.com.