Expand any CIDR notation into its complete IP range. View all individual IP addresses or first/last for large ranges. Instantly calculate total IP count.
Enter CIDR Notation
About the IPv4 Range Expander
The IPv4 Range Expander is a powerful networking tool that takes CIDR notation and expands it into the complete range of IP addresses. For small subnets (up to /20), it displays every individual IP address. For larger subnets, it shows the first and last IP along with the total count. This is invaluable for network planning, IP allocation tracking, firewall rule creation, and understanding exactly which addresses fall within a given subnet.
How to Use the Range Expander
Enter CIDR Notation: Type a CIDR notation like 10.0.0.0/28 into the input field.
Click Expand: Press the "Expand Range" button to generate the complete IP range.
View Results: For small ranges (/20 and larger prefix), see every IP. For larger ranges, see first/last with total count.
Copy the Output: Select and copy the IP list for use in firewall rules, documentation, or scripts.
Features
Full IP EnumerationFor subnets with up to 4,096 IPs, displays every individual address in the range.
Range SummaryFor larger subnets, shows first and last IP with total count for quick reference.
Subnet StatisticsDisplays first IP, last IP, total IPs, and prefix length in a clear stats panel.
Copy OutputCopy the complete IP list or range summary to your clipboard with one click.
Input ValidationValidates CIDR notation and IP addresses, providing clear error messages for invalid inputs.
Scrollable OutputLarge IP lists are displayed in a scrollable container for easy browsing without page overflow.
Benefits of Using This Tool
Manually expanding CIDR ranges is tedious and error-prone. This tool instantly generates the complete list of IPs, which you can use for firewall whitelist creation, DHCP pool planning, network scanning target lists, and documentation. Understanding the exact IPs in a range helps prevent misconfigurations and security vulnerabilities caused by incorrect subnet assumptions.
Who Uses This Range Expander?
Firewall AdminsGenerate IP lists for whitelist/blacklist rules, security group configurations, and ACL entries.
Network PlannersVisualize IP allocations, plan DHCP pools, and verify subnet sizing for new network segments.
Penetration TestersCreate target IP lists for network scanning and vulnerability assessment of specific subnets.
Cloud EngineersPlan VPC subnet allocations, security group rules, and network ACL configurations for cloud deployments.
Why TooliFyra's Range Expander?
TooliFyra's IPv4 Range Expander provides the most flexible output of any online range expander. It intelligently chooses between full enumeration and summary based on subnet size, preventing browser overload while still providing complete information. The clean output format makes it easy to copy IPs for use in scripts, configuration files, and documentation.
Frequently Asked Questions
A CIDR (Classless Inter-Domain Routing) range defines a block of IP addresses using a base address and a prefix length. For example, 192.168.1.0/24 represents all addresses from 192.168.1.0 to 192.168.1.255, providing 256 total addresses.
For very large subnets (e.g., /8 with 16 million IPs), listing every address would overwhelm the browser. Instead, we show the first and last IP along with the total count, which provides the same information in a more practical format.
Absolutely! The IP list output can be directly copied and used in firewall configurations, security group rules, or any system that accepts comma-separated or newline-separated IP lists.
This tool supports all valid CIDR prefix lengths from /0 (4 billion IPs) to /32 (single IP). For ranges larger than /20, it displays a summary with first/last IP and total count instead of listing every address.
