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developer validator

CIDR Validator

Validate IPv4/IPv6 CIDR blocks and view the normalized network address.

Results

Paste input and validate locally.
Status
Ready when you validate.
Details
Ready when you validate.
Network
Ready when you validate.
Prefix length
Ready when you validate.
Family
Ready when you validate.

Rules & checks

Parses IPv4 and IPv6 CIDRs and checks prefix length.

Shows the normalized network address.

Runs fully in your browser; no data leaves the page.

When to use it

  • QA firewall or security group rules
  • Validate CIDRs in Terraform/k8s manifests
  • Check user-provided network ranges in dashboards

Tips

  • Keep prefixes within 0–32 for IPv4 and 0–128 for IPv6
  • Normalize ranges before storing to avoid duplicates

Examples

IPv4 /24

  • 192.168.1.0/24 -> valid

IPv6 /64

  • 2001:db8::/64 -> valid

Invalid prefix

  • 10.0.0.0/33 -> invalid prefix

FAQs

Is anything uploaded?
No. Parsing happens locally and clears on refresh.
Do you expand the full range?
No. We show the normalized network and prefix.

Related validators

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IPv4 Validator

Confirm IPv4 addresses are well-formed before using them in configs or requests.

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IP Range Validator

Validate start/end IP ranges (IPv4 or IPv6) and check ordering.

Syntax-only; does not test reachability or overlaps.