I Built a Chrome Extension: Switch Browser Data

Introduction

When developing a web app, I often need to test with multiple accounts, such as an administrator and a regular user. And when regular users have several permission levels, the number of account types grows even more.

I used to go through “log out → log in with another account” every time I switched. It quietly ate up time and broke my rhythm, which got stressful.

Why I Didn’t Use an Existing Tool

If you’ve ever looked for “a tool to switch browser cookies,” you know there are a few options out there. What bothered me, though, was trust.

Cookies contain login session IDs. That means if a tool that handles cookies were malicious, it could in theory use that data to break into your accounts.

With closed-source tools, you can’t check what’s inside. I just couldn’t get comfortable using a tool while being unable to answer the question “Is this tool safe?”

What I Built: Switch Browser Data

So I decided to build one myself. One of the goals was to publish the code as open source so that anyone can look inside and check it.

Switch Browser Data is a Chrome / Edge extension that saves snapshots of browser data per domain and lets you switch between them with one click.

It supports the following data:

Data type	What it holds
Cookie	Login sessions and the like
localStorage	Data stored persistently in the browser
sessionStorage	Data that disappears when the tab is closed
IndexedDB	Structured data storage

All data is stored only on your device and is never sent anywhere.

How to Use It

1. Save a Snapshot

While logged in, open the popup, enter a snapshot name, and save. Naming them per account, like “Admin” or “Regular user A,” makes them easy to manage.

2. Switch with One Click

Just pick the snapshot you want from the dropdown. Reload the page, and that account’s state is restored.

Data is managed per domain, so it doesn’t affect other services’ data.

Source Code

The code is public on GitHub.

https://github.com/istb16/switch-browser-data-extension

It’s under the MIT license. Feel free to use it to see how it works or to verify that it doesn’t do anything suspicious.

Summary

• Switch between multiple accounts with one click, without “log out → log in”
• Cookies include login sessions, so I decided I needed a tool I could trust and built my own
• It’s open source, so you can read the code and check that it’s safe
• Works on both Chrome and Edge, and all data is stored locally