How to Intercept HTTPS Traffic from Chrome, Firefox, and Edge

Intercepting browser traffic is essential for web development, debugging API calls, testing security, and analyzing network behavior. This guide shows you how to capture HTTPS requests from any major browser using Fluxzy Desktop.

After completing this tutorial, you'll be able to:

• Capture all HTTP and HTTPS requests from Chrome, Edge, or Firefox
• Inspect request headers, response bodies, and timing data
• Choose the right interception method for your workflow
• Troubleshoot common certificate and proxy issues

Prerequisites: Fluxzy Desktop installed (download here)

Fluxzy offers two approaches for capturing browser traffic. Choose based on your needs:

┌─────────────────────────────────────────────────────────────────────┐
│                    METHOD COMPARISON                                │
├──────────────────────────────┬──────────────────────────────────────┤
│      LAUNCH & HOOK           │         SYSTEM PROXY                 │
│      (Recommended)           │                                      │
├──────────────────────────────┼──────────────────────────────────────┤
│  ✓ Zero configuration        │  ✓ Use existing browser sessions     │
│  ✓ Certificate pre-installed │  ✓ Keep your cookies & extensions    │
│  ✓ Works immediately         │  ✓ Monitor multiple browsers at once │
│  ✓ Isolated from your data   │  ✓ Capture from any HTTP client      │
├──────────────────────────────┼──────────────────────────────────────┤
│  ✗ Fresh browser session     │  ✗ Requires certificate installation │
│  ✗ No access to saved data   │  ✗ Platform-specific setup           │
└──────────────────────────────┴──────────────────────────────────────┘

The fastest way to start intercepting browser traffic. Fluxzy launches a browser instance with everything pre-configured.

• API debugging: Test endpoints without cached data interference
• Quick inspections: Start capturing in seconds
• Clean environment: No cookies or extensions affecting results
• First-time users: No setup required

Option A - Via Menu:

1. Open Fluxzy Desktop
2. Go to Capture > Launch and Hook
3. Select your browser (Chrome, Edge, or Firefox)
4. The browser opens with interception active - start browsing

Option B - Via Command Palette (fastest):

1. Press Ctrl+K (Windows/Linux) or Cmd+K (macOS)
2. Type the browser name (e.g., "chrome")
3. Select the launch action
4. Browser opens immediately

Option C - Via Applications Panel:

1. Look at the right sidebar
2. Click the Applications tab
3. Click your browser's icon

When you use Launch & Hook, Fluxzy:

┌─────────────────────────────────────────────────────────────────────┐
│                    LAUNCH & HOOK WORKFLOW                           │
├─────────────────────────────────────────────────────────────────────┤
│                                                                     │
│   1. Creates a temporary browser profile                            │
│      └── Isolated from your regular browsing data                   │
│                                                                     │
│   2. Installs Fluxzy certificate in that profile                    │
│      └── Browser trusts Fluxzy to decrypt HTTPS                     │
│                                                                     │
│   3. Configures proxy settings                                      │
│      └── All traffic routes through Fluxzy                          │
│                                                                     │
│   4. Launches browser with these settings                           │
│      └── Ready to capture immediately                               │
│                                                                     │
└─────────────────────────────────────────────────────────────────────┘

• Cannot attach to browsers that are already running
• No access to your saved passwords, cookies, or extensions
• Each session starts fresh (this is often a benefit for testing)

Use this method when you need to capture traffic from your regular browser session, including logged-in accounts, cookies, and extensions.

• Debugging production issues: Capture while logged into real accounts
• Testing with extensions: See how ad blockers or other extensions affect traffic
• Multi-browser monitoring: Capture from all browsers simultaneously
• Mobile device testing: Combined with device connection (see Connecting Devices)

The certificate allows Fluxzy to decrypt HTTPS traffic. This is a one-time setup.

1. Open Fluxzy Desktop
2. Go to Settings > Certificates
3. Click Install Certificate
4. Follow your operating system's prompts to trust the certificate

1. In Fluxzy, go to Capture > Start with OS traffic deflection
2. Fluxzy becomes your system's HTTP proxy
3. All HTTP/HTTPS traffic from the OS routes through Fluxzy

When using system proxy, you'll see traffic from all applications. Filter to focus on specific browsers:

Option A - Filter by Process Name (recommended on Windows):

1. Ensure process tracking is enabled in Settings
2. In the filter bar, select Process Name
3. Choose chrome.exe, msedge.exe, or firefox.exe

Option B - Filter by User Agent (works everywhere):

1. Create a new filter
2. Set filter type to Request Header Filter
3. Header name: User-Agent
4. Pattern: Chrome (or Firefox, Edge)
5. Operation: contains

Platform	Notes
Windows	Full support. Process filtering works without elevation.
macOS	Process tracking requires running Fluxzy with elevated privileges (sudo). User agent filtering works without elevation.
Linux	System proxy behavior varies by distribution and desktop environment. Some applications ignore system proxy settings. Consider using explicit proxy configuration.

Firefox uses its own certificate store and ignores system-installed certificates by default. Additional configuration is required when using the System Proxy method.

This tells Firefox to trust certificates from your operating system's certificate store.

1. Open Firefox
2. Type about:config in the address bar
3. Accept the warning if prompted
4. Search for security.enterprise_roots.enabled
5. Double-click to set value to true
6. Restart Firefox

If enterprise roots isn't suitable, import the certificate directly:

1. Export Fluxzy certificate (Settings > Certificates > Export)
2. Open Firefox Settings
3. Navigate to Privacy & Security > Certificates
4. Click View Certificates
5. Go to Authorities tab
6. Click Import
7. Select the exported Fluxzy certificate file
8. Check Trust this CA to identify websites
9. Click OK and restart Firefox

Your Scenario	Recommended Method
Quick API debugging	Launch & Hook
First time using Fluxzy	Launch & Hook
Need to stay logged into websites	System Proxy
Testing with browser extensions	System Proxy
Monitoring multiple browsers at once	System Proxy
Automated testing / CI pipeline	System Proxy + CLI
Don't want to install certificates	Launch & Hook

Symptoms: Fluxzy shows no exchanges after browsing.

Solutions:

1. Verify Fluxzy capture is started (green indicator in status bar)
2. For Launch & Hook: Ensure you're using the browser Fluxzy launched, not a regular instance
3. For System Proxy: Confirm system proxy settings are applied (check OS network settings)
4. Try accessing http://example.com (non-HTTPS) to verify basic connectivity

Symptoms: Browser shows "Your connection is not private" or similar warnings.

Solutions:

1. Certificate not installed - follow Step 1 of System Proxy setup
2. Certificate not trusted - re-run installation and ensure you grant trust
3. Firefox users - see Firefox-specific configuration above
4. Certificate expired - regenerate certificate in Settings > Certificates

Symptoms: Process filter shows "Unknown" or is empty.

Solutions:

1. Windows: Run Fluxzy as Administrator for full process visibility
2. macOS: Run Fluxzy with sudo or use User Agent filtering instead
3. Linux: Elevated privileges required; consider User Agent filtering

Symptoms: Chrome and Edge traffic appears, but Firefox shows nothing or certificate errors.

Solution: Firefox needs separate certificate configuration. See the Firefox-Specific Configuration section above.

Symptoms: Nothing happens when selecting a browser in Launch & Hook.

Solutions:

1. Verify the browser is installed in the default location
2. Close all existing instances of that browser
3. Check Fluxzy logs for error messages
4. Try a different browser to isolate the issue

1. Launch Chrome via Hook
2. Navigate to your application's login page
3. Open the exchange list in Fluxzy
4. Filter by path containing /auth or /login
5. Inspect request headers to verify tokens are sent correctly
6. Check response bodies for error messages

1. Launch a hooked browser
2. Open your web application
3. In Fluxzy, filter by the API domain
4. Look for OPTIONS preflight requests
5. Inspect Access-Control-* response headers

1. Set up System Proxy method
2. Open the same page in Chrome, Firefox, and Edge
3. Use process name filters to compare:
   • Are the same requests being made?
   • Are headers different between browsers?
   • Do response times vary?

• Core Concepts - Learn about filters, actions, and rules
• Connecting Devices - Capture traffic from mobile devices
• Capturing Raw Packets - Capture TCP/UDP level data
• Modifying Requests - Alter traffic with rules