How to Scan an IP Range on Windows (Free Tool + Command Line)

Scanning an IP range tells you which devices are active on your network — by checking every address in a subnet and reporting which ones respond. It's the starting point for network troubleshooting, security audits, and finding devices you need to configure.

This guide covers two methods: a free GUI tool that handles everything automatically, and built-in Windows commands for when you need a quick command-line approach.

Step 1: Find Your Network's IP Range

Before scanning, you need to know what IP range your network uses. Most home networks use either 192.168.1.x or 192.168.0.x. Here's how to confirm yours:

1. Press Windows + R, type cmd, press Enter
2. Type ipconfig and press Enter
3. Look for your active adapter (Ethernet or Wi-Fi) and note:
   • IPv4 Address — your PC's IP (e.g. 192.168.1.105)
   • Subnet Mask — usually 255.255.255.0 for home networks
   • Default Gateway — your router's IP (e.g. 192.168.1.1)
4. For a typical home network with subnet 255.255.255.0, your scan range is the first three octets of your IP address, with the last octet from 1 to 254. So if your IP is 192.168.1.105, scan 192.168.1.1 – 192.168.1.254.

Method 1: SterJo Fast IP Scanner — Recommended

SterJo Fast IP Scanner is a free, portable Windows tool that scans any IP range using multi-threaded ping. It checks over 1,000 IP addresses in under 30 seconds and shows each active host with its IP address, hostname (resolved via reverse DNS), and response time.

Step-by-Step:

1. Download SterJo Fast IP Scanner (1.7 MB, portable version available)
2. Run the tool — no installation required for the portable version
3. Enter your start IP (e.g. 192.168.1.1) and end IP (e.g. 192.168.1.254)
4. Click Scan
5. Active devices appear as they respond — with IP address, hostname, and status

Method 2: Ping Sweep via Command Prompt

If you need a quick check without downloading anything, Windows Command Prompt can do a basic ping sweep. This is slower than a dedicated tool but requires nothing extra.

For Loop Ping Sweep:

Open Command Prompt and run:

for /L %i in (1,1,254) do @ping -n 1 -w 100 192.168.1.%i | find "Reply"

This pings every address from 192.168.1.1 to 192.168.1.254 and prints only the successful replies. Replace 192.168.1 with your actual network prefix if different.

View ARP Cache After Pinging:

After a ping sweep, run arp -a to see the full ARP table — this shows the MAC addresses of devices that responded, which the ping output alone doesn't provide.

Method 3: ARP Command for Quick Results

The Windows ARP cache stores recently-seen devices automatically — no scanning required. View it instantly:

arp -a

This shows IP addresses and MAC addresses your PC has recently communicated with. It's not a full scan — it only covers devices your machine has directly talked to — but it's instant and requires no tools or commands beyond what Windows already provides.

When to Use IP Range Scanning

• Find a device's IP address — Printer, NAS drive, Raspberry Pi, smart hub — scan to find which IP it was assigned
• Network inventory — Document all active hosts before a router replacement or network change
• IP conflict detection — Two devices with the same IP cause connectivity issues; a scan reveals duplicates
• Office network management — See all workstations and servers currently online without visiting each one
• Troubleshooting — Confirm whether a specific device is actually active on the network or unreachable
• Security audit — Identify unexpected hosts on your subnet

IP Scanner vs WiFi Network Scanner — Which to Use?

Both tools discover network devices, but they're optimized for different tasks:

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