URL Percent-Encoding Validation Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching url percent-encoding validation, ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// URL Percent-Encoding Validation
// ReDoS-safe | RegexVault — Web & Network > URL

package validation

import "regexp"

var urlPercentencodingValidationRe = regexp.MustCompile(`^(?:[a-zA-Z0-9\-._~!$&'()*+,;=:@/?#\[\]]|%[0-9a-fA-F]{2})*$`)

func ValidateUrlPercentencodingValidation(s string) bool {
    return urlPercentencodingValidationRe.MatchString(s)
}

// Example
// fmt.Println(ValidateUrlPercentencodingValidation("/path/to%20resource")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > URL category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. 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

Technical Notes

This pattern validates encoding structure, not meaning. %2F is technically valid encoding but may have semantic implications (encoded forward slash vs. path separator) that require application-level handling.