IP Address Validator
IP Address Validator strictly checks four-part dotted IPv4 values and performs only a lightweight plausibility screen for IPv6-looking text. A positive IPv6 result means the text uses hexadecimal characters and colons; it is not full RFC validation and must not be used as a security boundary.
Runs locally — files stay on your deviceDoes “Plausible IPv6 syntax” prove an IPv6 address is valid?
No. It is deliberately a basic syntax screen; use a standards-compliant parser for authoritative validation.
IPv4 validation and IPv6 screening have different strength
IPv4 consists of four decimal octets from 0 through 255. IPv6 uses eight 16-bit hexadecimal groups with compression rules, embedded forms, and other constraints that require a complete parser.
How it works
The tool trims the input. IPv4 must have four dotted numeric groups no greater than 255; IPv6-like input must contain only hexadecimal digits and colons and include at least one colon.
Key concepts
Syntax is not reachability
No DNS lookup, route, interface, or host is contacted.
IPv6 support is intentionally basic
The result says plausible rather than standards-valid.
When to use it
- Catch obvious IPv4 typing errors.
- Triage whether text resembles IPv4 or IPv6.
- Check a value before manual debugging.
When not to use it
- Do not rely on the IPv6 result for access control.
- Do not assume a syntactically valid address is assigned or reachable.
- Do not use it to classify public, private, multicast, or reserved space.
Worked examples
Ordinary IPv4
- Input
192.0.2.40- Expected output
Valid IPv4 address
It contains four octets within range.
Out-of-range octet
- Input
192.0.2.999- Expected output
Invalid IP address
999 exceeds 255.
IPv6-like text
- Input
2001:db8::1- Expected output
Plausible IPv6 syntax
A complete IPv6 parser is still required for authoritative use.
Common mistakes
Treating plausible as valid
The IPv6 branch does not enforce every structural rule. Correction: Validate again with a full IP-address library.
Expecting a connectivity test
The tool only inspects text. Correction: Use authorized network diagnostics separately.
Using syntax as trust
An address string can be valid but unsafe or inappropriate. Correction: Apply range and policy checks after parsing.
Best practices
- Use canonical parsers in production systems.
- Normalize only after successful validation.
- Keep syntax, classification, DNS, and connectivity checks separate.
Related operations and differences
CIDR to Range
Choose CIDR to Range when you need to calculate an IPv4 network and broadcast address.; use IP Address Validator specifically for ip validate.
Private IP Checker
Choose Private IP Checker when you need to check common private and reserved IPv4 ranges.; use IP Address Validator specifically for ip validate.
cURL Command Builder
Choose cURL Command Builder when you need to build a basic cURL command from manual fields.; use IP Address Validator specifically for ip validate.
DMARC Record Generator
Choose DMARC Record Generator when you need to generate a basic DMARC policy record.; use IP Address Validator specifically for ip validate.
Fetch Request Builder
Choose Fetch Request Builder when you need to build a browser fetch request snippet.; use IP Address Validator specifically for ip validate.
HTTP Header Formatter
Choose HTTP Header Formatter when you need to normalize spacing in pasted HTTP headers.; use IP Address Validator specifically for ip validate.
Limitations and privacy
- IPv6 validation is a basic character-and-colon screen.
- No zone identifiers, DNS names, ports, CIDR prefixes, or reachability are validated.
- IPv4 leading-zero semantics are not normalized.
The entered network data is processed locally in this browser.
Frequently asked questions
Does it contact the address?
No.
Are hostnames accepted?
No.
Is IPv6 validation complete?
No, it is a plausibility screen.
Does a valid result mean the address is public?
No.