Semver library that offers utilities, version constraint parsing and validation.

Fund package maintenance!

Installs: 298 992 766

Dependents: 510

Suggesters: 7

Security: 0

Stars: 3 092

Watchers: 15

Forks: 74

Open Issues: 3

3.4.0 2023-08-31 09:50 UTC


Semver (Semantic Versioning) library that offers utilities, version constraint parsing and validation.

Originally written as part of composer/composer, now extracted and made available as a stand-alone library.

Continuous Integration PHP Lint PHPStan


Install the latest version with:

composer require composer/semver


  • PHP 5.3.2 is required but using the latest version of PHP is highly recommended.

Version Comparison

For details on how versions are compared, refer to the Versions article in the documentation section of the website.

Basic usage


The Composer\Semver\Comparator class provides the following methods for comparing versions:

  • greaterThan($v1, $v2)
  • greaterThanOrEqualTo($v1, $v2)
  • lessThan($v1, $v2)
  • lessThanOrEqualTo($v1, $v2)
  • equalTo($v1, $v2)
  • notEqualTo($v1, $v2)

Each function takes two version strings as arguments and returns a boolean. For example:

use Composer\Semver\Comparator;

Comparator::greaterThan('1.25.0', '1.24.0'); // 1.25.0 > 1.24.0


The Composer\Semver\Semver class provides the following methods:

  • satisfies($version, $constraints)
  • satisfiedBy(array $versions, $constraint)
  • sort($versions)
  • rsort($versions)


The Composer\Semver\Intervals static class provides a few utilities to work with complex constraints or read version intervals from a constraint:

use Composer\Semver\Intervals;

// Checks whether $candidate is a subset of $constraint
Intervals::isSubsetOf(ConstraintInterface $candidate, ConstraintInterface $constraint);

// Checks whether $a and $b have any intersection, equivalent to $a->matches($b)
Intervals::haveIntersections(ConstraintInterface $a, ConstraintInterface $b);

// Optimizes a complex multi constraint by merging all intervals down to the smallest
// possible multi constraint. The drawbacks are this is not very fast, and the resulting
// multi constraint will have no human readable prettyConstraint configured on it
Intervals::compactConstraint(ConstraintInterface $constraint);

// Creates an array of numeric intervals and branch constraints representing a given constraint
Intervals::get(ConstraintInterface $constraint);

// Clears the memoization cache when you are done processing constraints

See the class docblocks for more details.


composer/semver is licensed under the MIT License, see the LICENSE file for details.