Semver Checker

Parse, compare, and validate Semantic Versioning 2.0.0 strings. Check which of two versions is greater (with full prerelease precedence), test whether a version satisfies an npm-style range (^, ~, comparators, hyphen, ||), and bump major/minor/patch/prerelease. Runs 100% client-side.

Validators & Testers

cosmodev ~/tools/semver

Compare two versions

Version A

Version B

1.2.3 is less than 1.2.10

Range check

Version

Range

satisfies1.2.5 ∈ ^1.2.0

Bump version

cosmodev ~/docs/semver.md

What it does

The Semver Checker works with Semantic Versioning 2.0.0 strings. Compare two versions to see which is greater (with correct prerelease precedence - 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0), test whether a version satisfies an npm-style range (^, ~, comparators, hyphen ranges, ||), and bump major / minor / patch / prerelease in one click. Everything runs 100% client-side - no version string ever leaves your browser.

How to use it

Compare - enter two versions in Version A and Version B. The arrow between them and the verdict line tell you which is greater (or that they are equal).
Range check - enter a version and a range expression (e.g. ^1.2.0, ~1.0.0, >=1.2.3 <2.0.0, 1.0.0 || 2.0.0). A green satisfies or red no match badge shows the result.
Bump - enter a version, then click Major, Minor, Patch, or Prerelease to compute the next version and copy it.
Copy share link to send the exact inputs to someone else.

Examples

Compare (prerelease ordering)

1.0.0 vs 1.0.0-beta → 1.0.0 is greater than 1.0.0-beta (a release always outranks its prereleases).

1.2.3 vs 1.2.10 → 1.2.3 is less than 1.2.10 (numeric, not lexicographic - 10 > 3).

Range check

1.5.0 against ^1.2.0 → satisfies (compatible-with stays inside major 1).

1.2.2 against ^1.2.3 → no match (^1.2.3 requires >=1.2.3).

1.5.0 against >=1.2.0 <2.0.0 || 3.0.0 → satisfies (the first AND clause holds).

Bump

1.2.3 → Major 2.0.0 · Minor 1.3.0 · Patch 1.2.4 · Prerelease 1.2.4-0

1.2.3-beta.2 → Prerelease 1.2.3-beta.3 (increments the trailing numeric identifier).

Good to know

Prerelease precedence follows the semver.org spec: numeric identifiers are compared by value and rank lower than alphanumeric ones; a version with no prerelease is always higher than one with. Build metadata (+…) is ignored for ordering.
Ranges support ^ (caret), ~ (tilde), >= > <= < =, */x wildcards, partials (1, 1.2), hyphen ranges (1.2.3 - 2.3.4), space-separated AND, and || OR - the same grammar npm uses in package.json.
Invalid input is reported inline rather than throwing: a malformed version or range shows a red warning instead of a verdict.
Shareable: all three sections’ inputs are encoded in the URL.
Private: all parsing happens locally - safe for any version string.
Related tools: Statistics Calculator, Markdown Table Generator, ASCII Table.