What does this CIDR and subnet validator check?
It checks CIDR notation, subnet masks, prefix lengths, and common IPv4 subnet formatting rules.
Validators
CIDR & Subnet Validator
Validate CIDR notation, subnet masks, and network prefix formats directly in your browser.
Tool
CIDR & Subnet Validator
Validate CIDR notation, subnet masks, and network prefix formats directly in your browser.
This tool runs in your browser. Your input is processed locally and is not uploaded.
About this Tool
Use this free CIDR & Subnet Validator to check CIDR notation, subnet masks, and network prefix values. It can help detect invalid prefixes, malformed subnet masks, out-of-range IP addresses, wrong separators, and inconsistent IPv4 network notation. The validation runs directly in your browser and does not perform network scans.
Examples
- 192.168.0.0/24
- 255.255.255.0
Frequently Asked Questions
Does this scan the network?
No. This tool only checks the format and structure of the CIDR or subnet value. It does not contact any hosts.
Is my subnet input uploaded?
No. The validation is designed to run locally in your browser.
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