IPv4 Address
Matches valid dotted-decimal IPv4 addresses such as 192.168.1.1.
Use word boundaries so the pattern finds addresses inside longer text without matching fragments of bigger numbers.
regexnetworkvalidation
Find
\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\bThe octet branches are order-sensitive: 25[0-5] and 2[0-4][0-9] must come before the permissive 0-199 branch, otherwise 25 matches first and truncates 250.
Common mistakes
- Dropping the word boundaries, which lets the pattern match inside strings like 999.1.1.1.
- Assuming every regex flavor treats \b identically between digits and dots.
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