What data does kosh collect?

According to the developer's disclosure on the Mozilla Add-ons listing, the extension doesn't require data collection. It requests permissions to read and modify bookmarks, store its own settings, and export bookmarks via downloads.

kosh: Bookmark Manager — A modern, open-source UI for your browser bookmarks

kosh: Bookmark Manager is a free, open-source Firefox extension that provides a modern, clean interface on top of your browser's built-in bookmarks. Instead of replacing your bookmarks with a separate service, it works directly with Firefox's native bookmarks — so there's nothing to migrate or sync — and adds simpler browsing, organization, tagging, search, and export. It's a lightweight, single-purpose add-on (131 KB) aimed at Firefox users who find the default bookmark manager clunky but don't want to move to a third-party bookmarking service.

Key Features

Works with native bookmarks

Operates directly on your browser's built-in bookmarks — no migration, no separate collection to maintain, and it uses only the permissions needed to read, modify, and export them.

Organize and tag bookmarks

Browse, organize, and manage bookmarks with a modern UI, including tagging as described on the extension's listing.

Search bookmarks

Search through your existing bookmarks from a clean, focused interface.

Export bookmarks

Includes the ability to export your bookmarks (the extension requests download permissions for this).

Lightweight and privacy-friendly

A small 131 KB add-on that stores only extension settings locally and, per the developer, collects no user data.

How It Works

Install the Firefox add-on

Download kosh from Mozilla Add-ons and it runs inside Firefox, replacing your usual view of the built-in bookmark manager.

Browse and organize existing bookmarks

kosh reads your browser's native bookmarks and presents them in a modern interface where you can browse, search, tag, and reorganize them.

Export when needed

Using its download permissions, kosh can export your bookmarks to a file.

Pros & Cons

Pros

Free and fully open source under GPL-3.0, with the code available on GitHub
Works with native browser bookmarks — no lock-in, migration, or separate account
Minimal permission footprint: bookmarks, extension settings, and downloads only
No data collection, according to the developer's disclosure on the listing
Very lightweight (131 KB) and simple to use

Cons

Who It's For

Best for

Firefox users who find the default bookmark manager hard to use
People who want a cleaner bookmark UI without moving to a third-party bookmarking service or creating an account
Users who prefer open-source extensions with minimal permissions and no data collection
Anyone who wants to search, tag, and reorganize bookmarks they already have in Firefox

Not ideal for

Chrome, Edge, or Safari users — kosh is a Firefox add-on
People looking for a cross-browser, cloud-synced bookmarking service

Use Cases

Cleaning up and reorganizing a large pile of accumulated Firefox bookmarks

Searching and tagging bookmarks without moving to an external service like Raindrop.io or Pinboard

Keeping bookmarks synced through Firefox's native sync while enjoying a better management UI

Exporting bookmarks to a file for backup or migration

FAQ

What does kosh: Bookmark Manager do?

kosh is a Firefox extension that gives your browser's built-in bookmarks a modern, clean interface. You can browse, search, tag, organize, and export your bookmarks without leaving the native bookmark system.

Do I need to migrate or import my bookmarks?

No. kosh works directly with your browser's native bookmarks, so you use your existing Firefox bookmarks — there's nothing to migrate and no separate collection to manage.

Is kosh free?

Yes. kosh is free and open source, licensed under the GNU General Public License v3.0 (GPL-3.0-only). The source code is available on GitHub at github.com/sndsabin/kosh.

Which browsers does kosh support?

kosh: Bookmark Manager