GlossaryNetworkingBeginner

Port Number

A port number is a numeric label that directs network traffic to the right program on a device. Combined with an IP address, it tells data exactly where to go.

Last updated June 8, 2026

Definition

A port number is a 16-bit value (0 to 65535) that identifies a specific service or application on a networked device. While an IP address locates the machine, the port number locates the exact program on that machine that should handle the connection.

How it works

When data arrives at a device, the operating system reads the destination port and hands the traffic to whichever application is listening there. Many services use well-known default ports, such as 80 for HTTP, 443 for HTTPS, and 53 for DNS. The pairing of an IP address and a port (for example 198.51.100.10:8080) is called a socket.

Why it matters for proxies and scraping

Every proxy is reached through a specific IP-and-port combination, so the port number is part of every proxy configuration. Providers assign ports to route traffic to the correct proxy type or protocol; for instance, an HTTP proxy and a SOCKS5 proxy on the same host often listen on different ports. Some providers also use a single rotating port that issues a fresh IP on each connection, making port choice a practical part of scraping setups.

  • Direct traffic to the correct application
  • Configure HTTP vs SOCKS5 proxy endpoints
  • Enable IP rotation through dedicated ports

Examples

1

80 (HTTP), 443 (HTTPS), 53 (DNS)

2

198.51.100.10:8080 (a proxy socket)

3

1080 (default SOCKS5 proxy port)

Common Use Cases

Configuring a proxy endpoint
Separating HTTP and SOCKS5 proxy traffic
Routing to the correct service on a server
Enabling rotating IPs via a dedicated port

Frequently Asked Questions

There is no single standard, but common proxy ports include 8080, 3128, and 8000 for HTTP proxies and 1080 for SOCKS5. Your provider tells you the exact port to use.
The port routes your traffic to the correct proxy service or protocol on the host. Providers may use different ports for HTTP versus SOCKS5, or a special rotating port that gives a new IP each connection.

Keep Learning

All terms

SOCKS5

SOCKS5 is the latest version of the SOCKS proxy protocol. It routes any kind of network traffic — TCP and UDP — between a client and a server through a proxy, with optional authentication and no awareness of the underlying application.

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HTTP Proxy

An HTTP proxy is an intermediary server that forwards web (HTTP/HTTPS) requests on your behalf, able to read, cache and filter traffic at the application layer.

Read definition

IP Rotation

IP rotation is the practice of automatically cycling through multiple IP addresses so that successive requests originate from different IPs.

Read definition

Forward Proxy

A forward proxy sits between clients and the internet, forwarding their outbound requests so the destination sees the proxy's IP instead of the client's.

Read definition
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