Phone Number Regex Go Validator

What Is Phone Number Regex in Go?

In Go (Golang), regular expressions are handled via the regexp standard library. Validating phone numbers involves checking for specific structures such as:

• Country codes (e.g. +91, +1)

• Area codes

• Optional separators like hyphens, spaces, or parentheses

• Variable number lengths depending on country or region

  
  

Phone number regex is especially useful in:

• Form validations during user signups

• Backend checks in APIs or databases

• SMS/call communication systems

• Telecom software and mobile apps

  
  

Core Features & Constructs (Go Regex)

Metacharacters

• . : Matches any character except newline. Example: /.23/ matches "a23", "x23"

• ^ : Anchors to the start of the string. Example: /^+91/ matches "+91xxxxx..."

• $ : Anchors to the end of the string. Example: /123$/ matches ending in "123"

• | : Acts as OR. Example: /landline|mobile/ matches either word

  
  

Character Classes

• [0-9] : Matches any digit from 0 to 9

• [^0-9] : Matches any non-digit character

• [a-zA-Z] : Matches any letter (lowercase or uppercase)

  
  

Predefined Classes

• \d : Matches a digit. Equivalent to [0-9]

• \D : Matches a non-digit character

• \s : Matches a whitespace character

• \S : Matches any non-whitespace character

  
  

Quantifiers

• * : Matches zero or more occurrences

• + : Matches one or more occurrences

• ? : Matches zero or one (optional)

• {n} : Matches exactly n times

• {n,} : Matches at least n times

• {n,m} : Matches between n and m times

  
  

Regex Pattern Example for Phone Numbers

Here’s a common regex pattern to validate international phone numbers:

^\+?[1-9]\d{1,3}?[-.\s]?\(?\d{1,4}?\)?[-.\s]?\d{1,9}([-.\s]?\d{1,9})?$

This matches:

• Country codes like +91, +44, +1

• Optional separators like hyphens, dots, and spaces

• Parentheses for area codes

  
  

Go Code Examples

Example 1: Basic Phone Validation

package main

import (
	"fmt"
	"regexp"
)

func main() {
	pattern := regexp.MustCompile(`^\+?[0-9]{10,15}$`)
	phone := "+14155552671"
	fmt.Println("Valid Phone:", pattern.MatchString(phone))
}

Try similar patterns in the Go Regex Tester

Example 2: Phone Numbers With Separators

package main

import (
	"fmt"
	"regexp"
)

func main() {
	pattern := regexp.MustCompile(`^$begin:math:text$?\\d{3}$end:math:text$?[-.\s]?\d{3}[-.\s]?\d{4}$`)
	phone := "(415) 555-2671"
	fmt.Println("Valid Format:", pattern.MatchString(phone))
}

Generate real numbers with Phone Number Generator

Example 3: Form Field Testing with Area Code

package main

import (
	"fmt"
	"regexp"
)

func main() {
	input := "+91-9876543210"
	regex := regexp.MustCompile(`^\+91[-\s]?[6-9]\d{9}$`)
	fmt.Println("Indian Mobile Number Valid:", regex.MatchString(input))
}

 Combine with Address Generator for full user test data.

 Pro Tips

• Always use regexp.MustCompile() for static patterns to avoid runtime errors.

• Use FindStringSubmatch() if you want to extract parts like area codes or extensions.

• Avoid overly greedy expressions like .*—use quantifiers like {10,15} for accuracy.

• Validate with actual test data from tools like the Phone Number Generator or Username Generator.

• Use (?i) prefix for case-insensitive matching when needed.

  
  

Combine with These Tools

• Phone Number Generator: Generate dummy phone numbers for validation.

• Email Generator: Pair with email for signup forms.

• Username Generator: Use in user profile creation.

• Address Generator: Simulate full contact forms.

• Password Generator: For complete user registration flow testing.

• UUID Generator: Combine for device/user IDs.

Use Cases

• Signup form validation

• E-commerce mobile verification

• Telecom API testing

• Fake data generation for QA teams

• Data migration and normalization

Regex for Other Languages

• JavaScript: Use in JavaScript Regex Tester

• Java: Try in Java Regex Tester

• Python: Test in Python Regex Tester