Proxy server address lookup: a checklist for IT and ops teams

Sooner or later someone in operations or IT is asked a simple question: which proxy is this machine using? The answer is a host and a port, written host:port. You might need it to troubleshoot a connection, to confirm whether a proxy is set at all, to document an office setup, or to copy the details into a new tool. Because a proxy can be configured in several places, this checklist goes through operating systems, browsers, managed networks and code in turn, then shows how to prove that what you found actually works.

What you are looking for

Every proxy configuration comes down to two values. The address is a hostname or an IP; the port is a number, 8080 for example. Proxies that require a login also have a username and password, which are normally stored apart from the address or asked for at connection time. If the proxies came from us, the dashboard lists every value in host:port format together with the credentials.

Where to look first

Windows: Settings and the command line

Where the proxy was set in Windows itself:

1. Go to Settings > Network & internet > Proxy.
2. Look at the Manual proxy setup section. With Use a proxy server switched on, the Address and Port fields contain what you need.
3. With Automatic proxy setup switched on instead, there is no address to read, only a Script address: the URL of a PAC file that names the real server.

A second opinion comes from Command Prompt:

netsh winhttp show proxy

The result is the machine-wide WinHTTP proxy. Some services rely on it rather than on the setting each user sees.

macOS: System Settings and Terminal

1. Go to System Settings > Network.
2. Click Details next to the connection in use.
3. The Proxies tab lists a server and port for each protocol in use; the labels to look for are Secure Web Proxy (HTTPS), Web Proxy (HTTP) and SOCKS.

To read them without the settings window, ask Terminal; this example queries the Wi-Fi service:

networksetup -getwebproxy Wi-Fi

Browsers that keep their own settings

Browsers generally take the system proxy, but not all of them, and not always:

• Chrome / Edge: both hand the job to the operating system, so the Windows and macOS steps above apply. Their own settings pages simply link to those screens.
• Firefox: in Settings, scroll down to Network Settings and choose Settings…. This panel holds a proxy configuration that belongs to Firefox alone, with HTTP, HTTPS and SOCKS hosts and ports.

Extensions are the other exception: a proxy extension shows the address in its own panel, not in the browser's or the operating system's settings.

Managed office networks

Company devices often receive their proxy from central IT, and it may never appear as a plain address. Three clues:

• A PAC file: automatic configuration points at a URL ending in .pac. Opening that URL in a browser shows the script and the servers it chooses between.
• WPAD (Web Proxy Auto-Discovery): nothing is configured on the device itself, because the network tells it which proxy to use.
• Environment variables. On Linux or a Mac, print them in a terminal:

echo $http_proxy
echo $https_proxy

A line such as http://proxy.company.com:8080 in the output is the address you are after. Windows keeps the equivalents, HTTP_PROXY and HTTPS_PROXY, under System Properties > Environment Variables.

Scripts and applications

For anything automated, read the code or the environment it runs in. A Python script using requests holds the address in a proxies dictionary; the host and port follow the @ sign:

proxies = {
    "http": "http://USER:PASS@HOST:PORT",
    "https": "http://USER:PASS@HOST:PORT",
}

An axios setup in Node.js often keeps host, port and login as separate fields:

const config = {
  proxy: {
    host: "HOST",
    port: PORT,
    auth: { username: "USER", password: "PASS" },
  },
};

In both snippets, HOST plus PORT is the proxy server address.

Is the address live? Two checks

An address on a screen is not proof of a working proxy, so run two checks. First, browse to our my IP tool with the proxy active: the IP shown should be the proxy's, not the office's. Second, enter the host:port and login in our proxy checker, which reports reachability, latency and exit IP from a single test. A 407 response points to bad credentials at a correct address; a timeout usually points at the host or port.

When there is no proxy

An empty result is also an answer: no proxy is configured and traffic leaves directly. The my IP tool settles it in seconds; if it shows the real office or home IP, nothing is in the path. Worth knowing, especially when everyone believed a proxy was active.

An address your team controls

When the aim is to have a proxy rather than to find one, the provider issues the address. Each of our plans shows its host:port and login in the dashboard from the moment it is provisioned. Pick the type for the work: datacenter for speed, residential or mobile for household and carrier IPs, or premium residential for demanding sites. All of them are on the proxies page.

Each platform stores the address in a predictable place, and a few clicks or one command will reach it. Record the host and port, note any credentials, and close with a check in our tools, so the address is known to work, not just known.