Numbers Only Regex: Match Digits Only in JavaScript and Python

Use this numbers only regex when a value must contain digits only, with no spaces, letters, signs, or separators. Below you will find the exact regex, copy-ready examples for JavaScript, Python, and HTML forms, plus common mistakes to avoid.

Numbers only regex

Use ^\d+$ to match a string that contains digits only from start to end.

Primary regex:

^\d+$

What it matches:

• 7
• 12345
• 20260514

What it does not match:

• 12 345
• -42
• 3.14
• abc123
• 123abc

Quick note: If you want to allow an empty value, use ^\d*$ instead.

What does ^\d+$ mean?

This pattern checks whether the entire string contains one or more digits only:

^\d+$

Explanation:

• ^ starts the match at the beginning of the string
• \d matches a digit from 0 to 9
• + requires one or more digits
• $ ends the match at the end of the string

This is the right pattern for values like IDs, counters, numeric form fields, and strings that must not contain spaces, letters, or punctuation.

Numbers only regex that allows an empty string

If an empty field should still be considered valid, use:

^\d*$

This version matches:

• ``
• 5
• 123456

This version does not match:

• 12 34
• 12.5
• A12

JavaScript example

Use this regex when you want to validate a digits-only string:

const digitsOnlyRegex = /^\d+$/;

digitsOnlyRegex.test("123456"); // true
digitsOnlyRegex.test("00123"); // true
digitsOnlyRegex.test("12 34"); // false
digitsOnlyRegex.test("-42"); // false
digitsOnlyRegex.test("3.14"); // false
digitsOnlyRegex.test("abc123"); // false

If the field is optional:

const optionalDigitsOnlyRegex = /^\d*$/;

optionalDigitsOnlyRegex.test(""); // true
optionalDigitsOnlyRegex.test("123456"); // true
optionalDigitsOnlyRegex.test("12-34"); // false

Python example

In Python, use a raw string and re.fullmatch() so the whole value must match:

import re

digits_only_regex = r"\d+"

bool(re.fullmatch(digits_only_regex, "123456"))   # True
bool(re.fullmatch(digits_only_regex, "00123"))    # True
bool(re.fullmatch(digits_only_regex, "12 34"))    # False
bool(re.fullmatch(digits_only_regex, "-42"))      # False
bool(re.fullmatch(digits_only_regex, "3.14"))     # False
bool(re.fullmatch(digits_only_regex, "abc123"))   # False

Optional field example:

import re

optional_digits_only_regex = r"\d*"

bool(re.fullmatch(optional_digits_only_regex, ""))       # True
bool(re.fullmatch(optional_digits_only_regex, "12345"))  # True
bool(re.fullmatch(optional_digits_only_regex, "12-34"))  # False

HTML form validation example

If you want to validate digits only in a form field, use the pattern attribute:

<input
  type="text"
  name="employee_id"
  inputmode="numeric"
  pattern="\d+"
  title="Please enter digits only"
/>

Notes:

• inputmode="numeric" helps mobile users open a numeric keyboard
• pattern="\d+" validates one or more digits
• if the field is optional, do not add required

Extract digits from a longer string

If your input contains other text and you want to extract numeric parts instead of validating the entire value, use a different regex:

\d+

JavaScript example:

"Order #584 shipped on 2026-05-14".match(/\d+/g);
// ["584", "2026", "05", "14"]

Use ^\d+$ for validation and \d+ for extraction. They solve different problems.

Common mistakes

1. Forgetting ^ and $

This is one of the most common mistakes:

\d+

This pattern finds digits anywhere inside a string, so it would match abc123xyz. If you need a digits-only value, use:

^\d+$

2. Using the digits-only regex for decimals or negative numbers

This page is for integers written as digits only. It will not match:

• -42
• 3.14
• 1,000
• 12 345

If you need signed numbers, decimals, currency values, or formatted numbers, use a different pattern.

3. Accidentally allowing empty values

Use:

^\d+$

when the field must contain at least one digit.

Use:

^\d*$

only when an empty string is valid.

4. Expecting this regex to validate phone numbers

Phone numbers often include:

• a leading +
• spaces
• hyphens
• parentheses

That means a phone number regex should usually be different from a strict digits-only regex.

Below is a simple regular expression that allows validating if a given string contains only numbers:

/^\d+$/

Example code in Javascript:

var numberRegex = /^\d+$/;
// Validate numbers
numberRegex.test('12122022'); // Returns true
numberRegex.test('Hey12122022x'); // Returns false

// Extract a number from a string
var numberRegexG = /\d$/g;
'Your message was viewed 203 times'.match(numberRegexG); // returns ['203']

Real number regex

Real number regex can be used to validate or exact real numbers from a string.

/^(?:-(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))|(?:0|(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))))(?:.\d+|)$/

Example code in Javascript:

var numberRegex = /^(?:-(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))|(?:0|(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))))(?:.\d+|)$/;
// Validate numbers
numberRegex.test('121220.22'); // Returns true
numberRegex.test('Hey12122022x'); // Returns false

// Extract a real number from a string
var numberRegexG = /(?:-(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))|(?:0|(?:[1-9](?:\d{0,2}(?:,\d{3})+|\d*))))(?:.\d+|)/g;
'Pi equals to 3.14'.match(numberRegexG); // returns ['3.14']

Notes on number only regex validation

In JavaScript you can also validate number by trying to parse it using a Number constructor and then using isNaN function of a Number class:

var number = Number('22.2x');
Number.isNaN(number); // returns true