Ajv
JSON Schema and JSON Type Definition validator for Node.js and browsers that compiles schemas into validation functions.
Ajv is a validator for JSON data against JSON Schema and JSON Type Definition. It generates code from a schema, so each schema becomes a validation function that the application calls on its data. The package is installed from npm, and browser bundles are also published on cdnjs. Error message translations come from the separate ajv-i18n package.
Worth knowing
Support for JSON Schema draft 04 is a separate package, ajv-draft-04, and the command-line tool is another package, ajv-cli. The project’s docs name both alongside the core package.
Identity
Rendering and deploy
Releases
Adoption
Sources
- 2026-11-04: links
ajv.js.org/ - 2026-11-04: links, Written in, GitHub stars
api.github.com/repos/ajv-validator/ajv - 2026-11-04: links
ajv.js.org/guide/getting-started.html - 2026-11-04: Maintainer, License, License model
github.com/ajv-validator/ajv/blob/master/LICENSE - 2026-11-04: Categories, Runtime, Minimum runtime, Multilingual, Install with
github.com/ajv-validator/ajv/blob/master/README.md - 2026-11-04: Current major version, Last release
api.github.com/repos/ajv-validator/ajv/releases/tags/v8.20.0 - 2026-11-04: First release
registry.npmjs.org/ajv - 2026-11-04: Install with
ajv.js.org/guide/environments.html - 2026-11-04: npm downloads a week
api.npmjs.org/downloads/range/2026-10-26:2026-11-01/ajv - 2026-11-04: Contributors
api.github.com/repos/ajv-validator/ajv/contributors?per_page=1 - 2026-11-04: Dependent packages, Dependent repositories
packages.ecosyste.ms/api/v1/registries/npmjs.org/packages/ajv