What fields are required?

"name" and "version" are required by npm; description, license, repository and author are recommended.

Does it check dependency ranges?

Yes, it flags dependency version ranges that don't look like valid semver or git/URL specifiers.

Is my package.json sent anywhere?

No, validation happens entirely in your browser.

Package.json Validator

Validate package.json fields, semver ranges, and scripts.

Works Offline

Privacy First

No Login

No API

package.json

Paste your package.json contents

Validation results

Required fields, semver ranges, scripts

Errors

Warnings

Info

Recommended field "license" is missing.
Recommended field "repository" is missing.
Recommended field "author" is missing.
No blocking errors found.

Scripts

build→vite build
dev→vite

About the Package.json Validator

Paste a package.json file and check for missing required or recommended fields, invalid semver versions and dependency ranges, malformed scripts, and other common mistakes.

Examples

Missing version

{ "name": "app" }

Output

Error: missing required field "version"

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser