ISBN-10 Validation Regex

Validate ISBN-10 book identification numbers with optional formatting and X check digit using regex pattern.

Pattern Breakdown

^(?:ISBN(?:-10)?:? )?(?=[0-9X]{10}$|(?=(?:[0-9]+[- ]){3})[- 0-9X]{13}$)[0-9]{1,5}[- ]?[0-9]+[- ]?[0-9]+[- ]?[0-9X]$

Components

Examples

Valid:

• 0-306-40615-2
• 0306406152
• ISBN 0-306-40615-2
• ISBN-10: 0-306-40615-2
• 0-306-40615-X

Invalid:

• 0-306-40615 (missing check digit)
• 0-306-40615-23 (too many digits)
• ISBN-13: 0-306-40615-2 (wrong prefix)

Implementation

JavaScript

const isbn10Regex = /^(?:ISBN(?:-10)?:? )?(?=[0-9X]{10}$|(?=(?:[0-9]+[- ]){3})[- 0-9X]{13}$)[0-9]{1,5}[- ]?[0-9]+[- ]?[0-9]+[- ]?[0-9X]$/;
isbn10Regex.test('0-306-40615-2'); // true
isbn10Regex.test('0306406152'); // true
isbn10Regex.test('ISBN 0-306-40615-2'); // true

Python

import re
isbn10_regex = r'^(?:ISBN(?:-10)?:? )?(?=[0-9X]{10}$|(?=(?:[0-9]+[- ]){3})[- 0-9X]{13}$)[0-9]{1,5}[- ]?[0-9]+[- ]?[0-9]+[- ]?[0-9X]$'
bool(re.match(isbn10_regex, '0-306-40615-2'))  # True

Go

isbn10Regex := regexp.MustCompile(`^(?:ISBN(?:-10)?:? )?(?=[0-9X]{10}$|(?=(?:[0-9]+[- ]){3})[- 0-9X]{13}$)[0-9]{1,5}[- ]?[0-9]+[- ]?[0-9]+[- ]?[0-9X]$`)
isbn10Regex.MatchString("0-306-40615-2") // true

Limitations

1. No checksum validation: Doesn't validate check digit algorithm
2. Complex pattern: Hard to read and maintain
3. Format only: Validates format, not actual ISBN validity

When to Use

• ISBN-10 format validation
• Book catalog systems
• Library management
• When you need ISBN format checking

For production, consider:

• Implementing checksum validation
• Using ISBN parsing libraries
• Supporting both ISBN-10 and ISBN-13
• Normalizing to standard format