Storage Transfer

Storage Transfer is a Chrome extension built for the part of development nobody enjoys: getting a real session into your local environment. Instead of logging in again on localhost, hand-copying tokens out of DevTools, or writing throwaway scripts, you pick the storage entries you need in one tab and push them into another — across domains, ports and environments.

The problem it solves

Debugging an issue that only reproduces for a logged-in user usually means reconstructing that user's state by hand. Auth tokens live in localStorage, feature flags in sessionStorage, and the session itself in an httpOnly cookie that DevTools will let you read but not faithfully recreate. Copying those by hand is slow and easy to get wrong — a missing sameSite or domain attribute is enough for the session to be silently rejected.

Storage Transfer makes that a six-click operation and preserves every attribute along the way.

Features

• All three storage types — localStorage, sessionStorage and cookies, each in its own tab in the popup.
• Selective transfer — check only the keys you want. Nothing else in the destination tab is touched.
• Full cookie fidelity — domain, path, secure, httpOnly, sameSite and expiration all survive the transfer, so the destination sees the same cookie the origin did.
• Smart destination picker — the tab list is searchable and sorted so localhost and dev domains surface first, instead of being buried under thirty open tabs.
• Scoped to real pages — the extension only acts on http:// and https:// tabs.

How it works

The popup reads the active tab's storage through the scripting API and the browser's cookie store, shows you what is there, and then writes the selected subset into the tab you choose. Cookies go through the cookies API so their attributes are set properly rather than serialised into a document.cookie string that would drop httpOnly.

Everything stays on the machine: there is no backend, no analytics and no telemetry. Nothing about the transferred data leaves the browser.

Tech stack

Manifest V3, TypeScript and React 19 for the popup, bundled by Vite with @crxjs/vite-plugin. Styling is Tailwind CSS v4 with shadcn/ui, and the whole thing runs on Bun.

Running it locally

bun install
bun run dev    # HMR while developing
bun run build  # production bundle into dist/

Then open chrome://extensions/, turn on developer mode, and load dist/ as an unpacked extension.

Usage

1. Open the tab that holds the data you want.
2. Click the extension icon.
3. Pick a storage type — Local, Session or Cookies.
4. Check the items to transfer.
5. Search for and select the destination tab.
6. Hit Transfer.

Permissions

Three permissions, all of them load-bearing: cookies for reading and writing the cookie store, scripting for reaching into a page's storage, and the <all_urls> host permission because the whole point is moving data between different origins.

Source is on GitHub under the MIT license.