EXT-05 · Dossier
Privacy — NetSniffer
Last Updated: August 10, 2026
Overview
NetSniffer ("the Extension") is a browser-based network traffic analyzer that helps developers and security professionals inspect HTTP/HTTPS requests and responses. This Privacy Policy explains how the Extension handles your data.
The Developer Does Not Receive Your Traffic
NetSniffer processes network traffic locally so it can provide its user-requested capture, inspection, replay, mocking, API-client, and export features. The developer does not receive or have access to captured traffic.
- We do NOT send captured traffic to the developer
- We do NOT use analytics or tracking services
- We do NOT use advertising or behavioral profiling
- We do NOT sell or share captured traffic with third parties
- We do NOT provide cloud storage for captured traffic
What the Extension Displays
When you use NetSniffer, it locally handles the following types of network traffic from browser tabs you choose to inspect:
- Network request/response URLs, methods, headers, and bodies
- HTTP status codes and timing information
- WebSocket connections and messages
This data can contain browsing activity, website content, authentication information, form data, personal communications, or other information included by the inspected site. Active captures are kept in bounded in-memory buffers and shown only to you unless you deliberately export them or use another user-directed feature described below.
Where Data is Stored
All captured network data is stored locally in your browser using:
- localStorage: For persistent settings, bookmarks, and session data
- In-memory buffers: For active capture sessions (cleared when the browser closes)
Data Retention
- Active session data: Retained in memory until you clear it or close the side panel
- Settings and preferences: Stored in localStorage until you uninstall the extension
- Bookmarks and annotations: Stored in localStorage until you delete them or uninstall the extension
Data Limits
The Extension implements a ring buffer that limits stored packets to prevent excessive memory usage (default: 5,000 packets per tab).
Security Measures
- Local-only storage: All data remains on your device
- Per-tab isolation: Each browser tab has its own isolated capture session
- No developer cloud: Captured data is not sent to the developer, analytics providers, advertisers, or cloud storage
- Session cleanup: Data is cleared when you close the side panel or browser
Sensitive Data Warning
Network traffic may contain sensitive information such as:
- Authentication tokens and API keys
- Session cookies
- Personal information in request/response bodies
- Credentials in HTTP headers
You are responsible for protecting this data. Do not share exported captures containing sensitive information.
Permissions Explained
The Extension requires the following permissions:
| Permission | Purpose |
|---|---|
debugger | Access Chrome DevTools Protocol to capture network traffic |
scripting | Execute user-triggered request replays in an isolated extension world |
activeTab | Scope replay helper access to explicit active-tab actions |
tabs | Identify which tab to capture network traffic from |
tabGroups | Organize monitored tabs into groups for better visual organization |
sidePanel | Display the network traffic analyzer interface |
| Loopback hosts | Connect to an optional user-started MCP companion on this computer |
User Controls
You have full control over your data:
- Clear captured data: Click the clear button to remove all captured packets
- Stop capture: Stop the capture session at any time
- Export data: Export captured data for external analysis
- Delete bookmarks/annotations: Remove saved items at any time
- Uninstall: Removing the extension deletes all stored data
Third-Party Services
NetSniffer does NOT integrate with analytics, advertising, crash-reporting, or developer-operated cloud services. The Extension:
- Does not use analytics (Google Analytics, Mixpanel, etc.)
- Does not use crash reporting services
- Does not include advertisements
- Removes remote font and other passive third-party resource requests
When you deliberately send or replay an API request, NetSniffer connects to the destination you selected and includes the request data you configured. When you start the optional netsniffer-mcp companion, the workspace exchanges commands, selected capture results, and exports with an authenticated loopback-only process on the same computer. NetSniffer does not start that companion or make those exchanges without the user's setup and action.
Children's Privacy
NetSniffer is a developer tool and is not intended for use by children under 13 years of age.
Changes to This Policy
We may update this Privacy Policy from time to time. Changes will be reflected in the "Last Updated" date at the top of this document.
Contact
If you have questions about this Privacy Policy or the Extension's data practices, please open an issue on our GitHub repository.
Summary
- Local processing - Captured traffic is processed on your device
- No developer access - Captured traffic is not sent to us
- No analytics or tracking - No telemetry of any kind
- User-directed connections only - Requests, exports, and optional loopback automation happen only when you initiate them
- You control everything - Clear data anytime, uninstall to remove all