package.json Validator & Dependency Analyzer

Validate package.json syntax, check npm semver version ranges, and detect missing required fields.

package.json Validator & Dependency Analyzer

Validate package.json syntax, check npm semver version ranges, and detect missing required fields.

Paste package.json Content:

✓ Valid JSON & Package Manifest

Total Dependencies: 3Total DevDependencies: 1

Manifest Audit Warnings (1):

Unpinned wildcard version detected in 'lodash': '*'

About This Tool

The package.json Validator inspects npm package manifests for JSON formatting errors, wildcards (`*`) or loose semver ranges in dependencies, missing repository/license fields, and duplicate script names.

Key Features

Validates npm `package.json` schema and JSON syntax

Flags risky wildcard (`*`) and unpinned dependency version ranges

Counts total `dependencies`, `devDependencies`, and `peerDependencies`

Checks required npm fields (name, version, license, description)

How to Use This Tool

Paste your `package.json` content into the editor.
Instantly view validation diagnostics, dependency metrics, and health warnings.
Fix identified issues before publishing or pushing to git.

Why Use This Tool

Prevent npm publish errors caused by malformed manifest fields.
Audit loose semver ranges that could introduce breaking upstream dependency bugs.

Pro Tips

Pinning dependencies with exact versions (`1.2.3`) or strict carets (`^1.2.3`) protects against supply-chain breakage.

Frequently Asked Questions

What are the essential required fields for an npm package?

An npm package requires at minimum `name` (lowercase, URL-safe) and `version` (strict SemVer, e.g. `1.0.0`). For public packages, `license` is also strongly recommended.

Why should I avoid using '*' as a dependency version?

Using `*` causes npm to install the newest available release regardless of breaking major updates, easily breaking your application build.

package.json Validator & Dependency Analyzer