Semantic Versioning Validation Regex

Validate semantic version numbers (SemVer) including major.minor.patch with optional pre-release and build metadata using comprehensive regex pattern.

Pattern Breakdown

^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$

Components

Detailed Breakdown

• (0|[1-9]\d*) - Version number: either 0 or positive integer without leading zeros
• (?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))? - Pre-release:
  • Optional hyphen -
  • Identifiers separated by dots
  • Can be numeric or alphanumeric
• (?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))? - Build metadata:
  • Optional plus +
  • Identifiers separated by dots

Examples

Valid:

• 1.0.0
• 2.1.3
• 10.20.30
• 1.0.0-alpha
• 1.0.0-alpha.1
• 1.0.0-alpha.1.beta
• 1.0.0+20130313144700
• 1.0.0-alpha+001
• 1.0.0-beta.2+exp.sha.5114f85

Invalid:

• 01.0.0 (leading zero in major)
• 1.00.0 (leading zero in minor)
• 1.0.00 (leading zero in patch)
• 1.0 (missing patch version)
• 1.0.0.0 (too many version parts)
• v1.0.0 (version prefix not supported)
• 1.0.0- (incomplete pre-release)

Implementation

JavaScript

const semverRegex = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$/;
semverRegex.test('1.0.0'); // true
semverRegex.test('2.1.3-alpha.1'); // true
semverRegex.test('1.0.0+20130313144700'); // true
semverRegex.test('01.0.0'); // false (leading zero)
semverRegex.test('1.0'); // false (missing patch)

Python

import re
semver_regex = r'^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$'
bool(re.match(semver_regex, '1.0.0'))  # True
bool(re.match(semver_regex, '2.1.3-alpha.1'))  # True
bool(re.match(semver_regex, '01.0.0'))  # False (leading zero)

Go

semverRegex := regexp.MustCompile(`^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`)
semverRegex.MatchString("1.0.0") // true
semverRegex.MatchString("2.1.3-alpha.1") // true
semverRegex.MatchString("01.0.0") // false (leading zero)

Limitations

1. Complex pattern: Very long and hard to read/maintain
2. No version comparison: Only validates format, doesn't compare versions
3. No range validation: Doesn't validate version ranges (e.g., ^1.0.0, ~2.1.0)
4. Format only: Validates format per SemVer spec, not semantic meaning
5. Performance: Complex pattern may be slower for very long strings

When to Use

• Semantic version validation
• Package version checking
• API version validation
• When you need strict SemVer format checking
• Version input forms

For production, consider:

• Using SemVer parsing libraries (e.g., semver npm package)
• Supporting version ranges if needed
• Implementing version comparison functions
• Handling version prefixes (e.g., v1.0.0)
• Using specialized version management libraries