Semver Validator
Validate semantic version strings online for free. Our validator checks against the Semver 2.0.0 specification for correct MAJOR.MINOR.PATCH format, pre-release identifiers, build metadata, leading zeros, range expressions, duplicates, and sort order. Supports batch validation with one version per line.
Enter one or more version strings (one per line) to validate against the Semver 2.0.0 specification. Checks MAJOR.MINOR.PATCH format, pre-release identifiers, build metadata, leading zeros, and common mistakes.
Why Use Our Semver Validator?
Instant Validation
Our tool to validate semver analyzes your content instantly in your browser. Validate Semver files of any size with zero wait time — get detailed error reports with line numbers in milliseconds.
Secure & Private Processing
Your data never leaves your browser when you use our semver validator online tool. Everything is processed locally using JavaScript, ensuring complete privacy and security for sensitive configuration data.
No File Size Limits
Validate large Semver files without restrictions. Our free Semver Validator handles any size input — from small configs to massive files with thousands of entries.
100% Free Forever
Use our Semver Validator completely free with no limitations. No signup required, no hidden fees, no premium tiers, no ads — just unlimited, free validation whenever you need it. The best free semver validator online available.
Common Use Cases for Semver Validator
Package Management
Validate version strings in package.json, Cargo.toml, setup.py, or any package manager configuration. Ensure correct MAJOR.MINOR.PATCH format and valid pre-release identifiers before publishing.
Release Management
Verify release version tags follow Semver 2.0.0 before creating Git tags or GitHub releases. Catch leading zeros, invalid pre-release labels, and formatting issues early.
API Versioning
Validate API version strings to ensure they communicate backward compatibility correctly. Major version increments signal breaking changes, minor versions add features, and patches fix bugs.
Dependency Auditing
Validate version constraints and ranges used in dependency files. Detect npm-style range operators (^, ~, >=) and ensure they reference properly formatted base versions.
Changelog Verification
Validate version numbers listed in changelogs and release notes. Check for duplicates, proper ordering, and format consistency across your project's version history.
CI/CD Version Gates
Validate version strings in CI/CD pipelines before building, tagging, or deploying. Ensure automated versioning tools produce spec-compliant version numbers.
Understanding Semver Validation
What is Semver Validation?
Semver validation is the process of checking Semantic Versioning 2.0.0 files (.txt) for syntax errors, structural issues, invalid values, duplicate keys, and specification compliance — helping you catch problems before deployment. Semver is widely used for communicating meaningful version information about software changes through a structured MAJOR.MINOR.PATCH format where incrementing each component signals breaking changes, new features, or bug fixes respectively. Our free semver validator online tool checks your content instantly in your browser. Whether you need to validate semver for npm package versioning, library releases, API versioning, Git tag validation, changelog version checking, dependency constraint auditing, CI/CD pipeline version gates, and release management, our tool finds errors accurately and privately.
How Our semver validator Works
- Input Your Semver Content: Paste your Semver content directly into the text area or upload a
.txtfile from your device. Our semver validator online tool accepts any Semver input. - Instant Browser-Based Validation: Click the "Validate Semver" button. Our tool analyzes your content entirely in your browser — no data is sent to any server, ensuring complete privacy.
- Review Detailed Error Reports: View a comprehensive list of errors with line numbers, descriptions, and severity levels. Fix issues with pinpoint accuracy using our clear error messages.
What Gets Validated
- Syntax Correctness: Checks for proper syntax including balanced brackets, correct string quoting, valid escape sequences, and proper key-value pair formatting.
- Data Types: Validates integers, floats, booleans, strings, datetimes, arrays, and inline tables conform to the Semver specification.
- Structural Integrity: Detects duplicate keys, conflicting table definitions, invalid table headers, and malformed sections.
- Line-by-Line Reporting: Every error includes its exact line number and a clear description, making it easy to find and fix issues in your Semver files.
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Frequently Asked Questions - semver validator
A semver validator is a tool that checks Semver files for syntax errors, structural issues, invalid values, and specification compliance. Our semver validator online tool processes everything in your browser — giving you instant error reports with line numbers and clear descriptions.
Our semver validator detects syntax errors (missing brackets, incorrect quoting), structural issues (duplicate keys, conflicting table definitions), invalid data types (malformed numbers, dates, strings), invalid escape sequences, and specification violations. Each error includes its exact line number for easy debugging.
Absolutely! Your data is completely secure. All validation happens directly in your browser using JavaScript — no data is ever uploaded to any server. Your configuration files, secrets, and sensitive data never leave your device.
Yes, our semver validator is 100% free with absolutely no hidden costs or limitations. There's no signup required, no premium tier, no usage limits, no file size restrictions, and no advertisements. Use it unlimited times for any project.
Yes! Our semver validator online tool handles files of any size. Since all processing happens in your browser, performance depends on your device, but modern browsers handle even very large Semver files efficiently.
Semantic Versioning (Semver) is a versioning specification that uses MAJOR.MINOR.PATCH format (e.g., 1.2.3). MAJOR increments for breaking changes, MINOR for backward-compatible features, and PATCH for backward-compatible bug fixes. Optional pre-release identifiers (-alpha.1) and build metadata (+build.123) can be appended.
Leading zeros are forbidden per Semver 2.0.0 specification to prevent ambiguity. For example, "01.02.03" is invalid — it must be "1.2.3". This rule applies to MAJOR, MINOR, PATCH components and numeric pre-release identifiers.
Pre-release identifiers (after "-") indicate a version is unstable and may not satisfy normal version requirements (e.g., 1.0.0-alpha < 1.0.0). Build metadata (after "+") is informational only and does not affect version precedence (e.g., 1.0.0+build.1 equals 1.0.0+build.2 in precedence).
Yes! While version ranges (^1.2.3, ~1.0.0, >=2.0.0, 1.x) are not part of Semver 2.0.0, our validator detects and identifies them as npm/node-semver range syntax. It will warn that they are range expressions rather than single versions.
Yes! Enter one version per line to validate them all at once. The validator will check each version individually, detect duplicates between them, and verify if the versions are in sorted order.