Ipv4 Range Expander

Free online tool. All processing is client-side. No signup needed.

How to Use the Ipv4 Range Expander

1. Enter your input values above
2. Results update automatically
3. Copy or download the output

What is a Ipv4 Range Expander?

An IPv4 Range Expander takes a CIDR notation block (192.168.1.0/24) or IP range (192.168.1.1-192.168.1.50) and expands it into the complete list of individual IP addresses — essential for generating allowlists/blocklists, network scanning, and inventory management. A /24 subnet contains 256 addresses; manually listing them is tedious and error-prone.

How Does It Work?

Enter a CIDR block or hyphenated IP range. The expander calculates range boundaries and generates every IP address in sequence. Output formats include: newline-separated list, comma-separated, JSON array, and tool-specific formats (Nmap targets, Ansible inventory). For large ranges (>4,096 IPs), the expander warns and offers sampled output.

Formula

CIDR to IP Range: Network Address = IP AND Mask, Broadcast = IP OR (NOT Mask)\nUsable = Network+1 to Broadcast-1\nCount = 2^(32−CIDR) addresses total\nExample: 10.0.0.0/28 → 16 addresses (14 usable: .1 to .14)

Who Uses This Tool?

• Network admins generating IP lists for firewall rules and ACLs
• DevOps creating Ansible inventory files for server ranges
• Penetration testers defining scan targets for assessments
• DHCP server configuration: listing available static IPs
• Documentation: enumerating all IPs in a subnet for diagrams

Pro Tips

• Be careful with large ranges: a /16 = 65,536 IPs. The expander caps output at 65,536 and offers sampling above that
• Cloud providers reserve the first 4 IPs + last 1 per subnet. A /24 yields 251 usable addresses, not 254
• Use comma-separated output for Nmap targets, newline-separated for shell scripts, JSON arrays for API payloads

Frequently Asked Questions about Ipv4 Range Expander

What's the largest range I can expand?

Any valid CIDR (/0 to /32). The expander caps output at 65,536 addresses with sampling for larger ranges.

Can I merge multiple ranges?

Yes — enter multiple CIDR blocks or ranges (one per line) and the expander merges and deduplicates them automatically.

Free online Ipv4 Range Expander — no signup, 100% client-side processing. All data stays in your browser.