Snackgnito: An Open-Source Chrome Extension for Isolated Browser Sessions
"Testing multiple accounts in the same browser should not require constantly logging out, clearing cookies, or opening separate browser profiles."
⚡ TL;DR
Snackgnito is an open-source, privacy-focused Chrome Extension built on Manifest V3. It creates single-use, isolated tabs with virtual in-memory cookie containers. By intercepting Set-Cookie headers and proxying DOM storage (document.cookie, localStorage), it allows developers, QA engineers, and power users to log into multiple accounts on the same site simultaneously without session mixing or polluting main browser storage.
For developers working on SaaS products, admin dashboards, eCommerce platforms, multi-tenant applications, and authentication systems, testing multiple user accounts is a routine part of daily engineering.
You might need an administrator account open in one session, a manager account in another, and a customer account with restricted permissions in a third. The problem is that modern web browsers normally share global cookie state across tabs.
That makes testing side-by-side roles frustrating. The typical workarounds include logging out repeatedly, creating multiple Chrome user profiles, or juggling multiple browsers (Chrome, Firefox, Safari).
Snackgnito was created to solve this problem by providing **tab-level session isolation**. It is developed as an open-source tool by Vivago Technologies and is available on GitHub.
What is Snackgnito?
Snackgnito is a lightweight Chrome extension that intercepts and manages cookies in a virtual container. Instead of persisting session tokens to your browser's native cookie store, Snackgnito manages isolated cookie jars inside an in-memory Map attached to specific tab IDs.
How Snackgnito Works Under the Hood
Snackgnito operates seamlessly across both the network level and the DOM level:
1. Network Level Interception
Utilizes Chrome Manifest V3 declarativeNetRequest rules and background session monitoring. When a request receives a Set-Cookie header in a Snackgnito tab, Snackgnito strips the header before native browser storage can persist it, saving the token inside an isolated session Map instead. Outgoing requests automatically inject the stored Cookie header corresponding to that specific tab container.
2. DOM Execution Proxying
Injects a proxy script directly into the page's MAIN execution world. This script intercepts client-side JavaScript calls to document.cookie, localStorage, and sessionStorage. Web applications behave as though they have full storage access, while actually interacting with an isolated, in-memory proxy.
3. Ephemeral by Default
Once you close a Snackgnito tab, its virtual cookie jar and storage proxy are completely wiped from memory. No residual session tokens, trackers, or leftover cookies remain in your main browser storage.
Building Complex SaaS or Browser Extensions?
Vivago Technologies specializes in custom SaaS platforms, modern web apps, and extension engineering with strict performance and security standards.
Key Features & Developer Workflows
- Instant Tab Conversion: Open any link in an isolated Snackgnito tab from the context menu, or convert your current active tab instantly with the
Alt+Vkeyboard shortcut. - Child Tab Inheritance: Middle-clicking links or opening new tabs from within a Snackgnito tab automatically inherits the isolated session context.
- Multi-Role SaaS Testing: Simultaneously test Admin dashboards, Manager views, and End-User permissions side-by-side without identity collisions.
- Clean Analytics & Privacy: Prevents third-party trackers from linking session activity across isolated tabs to your primary browser identity.
Snackgnito vs Chrome Incognito Mode
| Criteria | Standard Incognito | Snackgnito |
|---|---|---|
| Isolation Scope | Window-level (all incognito tabs share 1 session) | Tab-level (each tab is isolated) |
| Concurrent Accounts | Max 2 (1 Normal + 1 Incognito) | Unlimited simultaneous accounts |
| Storage Persistence | Persists until all Incognito windows close | Wiped immediately on tab close |
| Workflow Friction | Requires separate window management | Same window, standard tab bar |
Developer Installation Guide
Snackgnito is built with TypeScript, Vite, Tailwind CSS, and Chrome Manifest V3. You can load it manually in Developer Mode:
# 1. Clone the repository git clone https://github.com/nowshadabir/snackgnito.git cd snackgnito# 2. Install dependencies & build npm install npm run build
- Open Chrome and navigate to
chrome://extensions/ - Enable Developer mode in the top right corner.
- Click Load unpacked.
- Select the generated
dist/directory from the build step.
Open Source & Source Code
Snackgnito is open source under the MIT License and maintained by Vivago Technologies.
🔗 GitHub Repository: https://github.com/nowshadabir/snackgnito
Learn more about how Vivago Technologies builds modern SaaS applications by exploring our SaaS Development Services and AI Integration Services.