Explicit Capturing Mode

The explicit capturing mode in Fiddler Everywhere lets you capture traffic from any application that supports manual HTTP proxy configuration. Unlike system capturing, explicit capturing does not modify your operating system proxy settings—only applications you explicitly point at the Fiddler proxy are captured. This gives you surgical control over which traffic appears in the Live Traffic grid.

When to Use Explicit Capturing

Use explicit capturing when:

• You want to capture traffic from a single application without intercepting system-wide traffic.
• Your environment restricts changes to the OS proxy (for example, corporate policy or VPN software that resets proxy settings).
• You are testing a remote device or a specific CLI tool and want to route only that traffic through Fiddler.
• System capturing conflicts with other tools on your machine (for example, a local development proxy or a VPN client).

For general desktop debugging where capturing all applications is acceptable, prefer system capturing. For browser-only scenarios without certificate setup, prefer independent browser capturing.

Prerequisites

• Install and trust the Fiddler CA certificate on the machine or device running the target application.
• Note the Fiddler proxy port. The default is 8866; verify or change it through Settings > Connections > Fiddler listens on port.

Fiddler Proxy Address

When Fiddler Everywhere is running, it exposes a local HTTP(S) proxy at:

127.0.0.1:8866

Point your target application to this address to start capturing its traffic. The port number is configurable through Settings > Connections > Fiddler listens on port.

To find your machine's local IP address for remote device scenarios, open Settings > Connections. The panel displays the address remote clients should use (for example, 192.168.1.105:8866).

Capturing from CLI Tools

curl

Pass the -x flag to route a curl request through Fiddler:

curl --url https://api.example.com/v1/orders -x 127.0.0.1:8866 --ssl-no-revoke -v

The --ssl-no-revoke flag prevents certificate revocation errors on Windows. On macOS and Linux, use --proxy-cacert or trust the Fiddler CA system-wide instead.

wget

wget -e use_proxy=yes -e http_proxy=127.0.0.1:8866 -e https_proxy=127.0.0.1:8866 https://api.example.com/v1/products

PowerShell (Invoke-WebRequest)

$proxy = New-Object System.Net.WebProxy("http://127.0.0.1:8866", $true)
$session = New-Object Microsoft.PowerShell.Commands.WebRequestSession
$session.Proxy = $proxy
Invoke-WebRequest -Uri "https://api.example.com/v1/inventory" -WebSession $session

Capturing from Desktop Applications

Most GUI applications expose a proxy or network settings panel. Configure it with:

Examples of applications that support manual proxy settings: Postman, Insomnia, Charles Proxy clients, Java applications using system properties, and most browsers in non-system-proxy mode.

Capturing from Python Applications

Route requests library calls through Fiddler without changing system environment variables:

import requests

proxies = {
    "http": "http://127.0.0.1:8866",
    "https": "http://127.0.0.1:8866",
}

response = requests.get(
    "https://api.example.com/v1/shipments",
    proxies=proxies,
    verify=False  # Only use during local debugging; remove in production
)

print(response.json())

Setting verify=False disables TLS verification. Use this only for local debugging sessions with Fiddler. In production code, always validate TLS certificates.

For production-safe verification, point the verify parameter to the exported Fiddler CA certificate file instead of disabling verification entirely:

response = requests.get(
    "https://api.example.com/v1/shipments",
    proxies=proxies,
    verify="/path/to/FiddlerRootCertificate.crt"
)

Capturing from Node.js Applications

Set the https-proxy-agent package to route Node.js HTTPS requests through Fiddler:

import https from "https";
import { HttpsProxyAgent } from "https-proxy-agent";

const agent = new HttpsProxyAgent("http://127.0.0.1:8866");

https.get(
  "https://api.example.com/v1/transactions",
  { agent },
  (res) => {
    let data = "";
    res.on("data", (chunk) => { data += chunk; });
    res.on("end", () => console.log(JSON.parse(data)));
  }
);

For applications using the axios library, pass the proxy configuration directly through the proxy option in the request config object.

Capturing from Remote Devices

Explicit capturing is the foundation for all remote device setups. Configure the remote device to use the Fiddler host machine's IP address as its proxy:

1. Find your Fiddler host machine's local IP (for example, 192.168.1.105) through Settings > Connections.
2. On the remote device, set the HTTP proxy to 192.168.1.105:8866.
3. Install and trust the Fiddler CA certificate on the remote device.
4. Trigger traffic from the remote device; it appears immediately in the Fiddler Live Traffic grid.

For device-specific instructions, see:

• Android device setup
• iOS device setup
• Remote PC setup

Verifying the Configuration

After pointing your application at the Fiddler proxy:

1. Start Fiddler Everywhere.
2. Open the Traffic pane.
3. Trigger a request from your target application.
4. Confirm the request appears in the Live Traffic grid.

If no traffic appears, check the following:

• Fiddler Everywhere is running and listening on the expected port.
• The application proxy settings use the exact address and port Fiddler reports in Settings > Connections.
• The Fiddler CA certificate is installed and trusted on the capturing device.
• A firewall or security tool is not blocking the connection to 127.0.0.1:8866.

See Also

• Capturing Modes Overview
• Capturing System Traffic
• Capturing from Android Devices
• Capturing from iOS Devices
• Trusting the Fiddler CA Certificate