IPv4 in URL Context (http/https) Regex for Java
/^https?://(?:(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\.){3}(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])(?::(?:6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[1-9][0-9]{0,3}))?(?:/[^\s]*)?$/iWhat this pattern does
This page provides a comprehensive, battle-tested regular expression for matching ipv4 in url context (http/https), ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.
Java Implementation
// IPv4 in URL Context (http/https)
// ReDoS-safe | RegexVault — Web & Network > IPv4
import java.util.regex.Pattern;
public class Ipv4InUrlContextHttphttpsValidator {
private static final Pattern PATTERN =
Pattern.compile("^https?://(?:(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])\\.){3}(?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9])(?::(?:6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[1-9][0-9]{0,3}))?(?:/[^\\s]*)?$");
public static boolean validate(String input) {
return PATTERN.matcher(input).matches();
}
// Example
public static void main(String[] args) {
System.out.println(validate("http://192.168.1.1")); // true
}
}Test Cases
Matches (Valid) | Rejects (Invalid) |
|---|---|
http://192.168.1.1 | http://256.0.0.1 |
https://10.0.0.1:8443/api/v1 | ftp://192.168.1.1 |
http://127.0.0.1/index.html | http://192.168.1 |
https://8.8.8.8:53 | 192.168.1.1/path |
http://0.0.0.0/ | http://192.168.1.1:99999/path |
When to use this pattern
This pattern is drawn from the Web & Network > IPv4 category and carries a ReDoS-safe certification. That matters for Java developers because critical in Java applications since the JVM regex engine uses backtracking and is susceptible to ReDoS without careful pattern design. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.
Common Pitfalls
Do not use (.+) or (.*) for the path — use [^\s]* or a more specific character class to avoid catastrophic backtracking.
Technical Notes
The i flag makes the scheme case-insensitive (HTTP and HTTPS are valid). Path component uses [^\s]* which is bounded by whitespace, not by content — safe against ReDoS.
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