# ajv-validator/ajv

The fastest JSON schema Validator. Supports JSON Schema draft-04/06/07/2019-09/2020-12 and JSON Type Definition (RFC8927)

Repository: https://github.com/ajv-validator/ajv
Canonical: https://ross.abutalabs.com/products/ajv
Homepage: https://ajv.js.org
Language: TypeScript
License: MIT
License Family: permissive
Topics: json-schema, validator, ajv
Last push: 2026-05-12T07:38:47+00:00

## Health v2 (maintenance only)
Score: 81/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 82, release rhythm 69, longevity 100
- inputs: {"age_days": 4124, "days_push": 113, "days_rel": 131, "gap_med": 34.0, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 14813, forks 1041 (observed 2026-08-28T04:11:07.745973+00:00)

## What it is
Ajv is the fastest JSON Schema validator for JavaScript, compiling declarative schemas into optimized validation functions. It supports JSON Schema drafts 04 through 2020-12 and JSON Type Definition (RFC 8927), running in Node.js, browsers, and other JS environments.

## Use cases
- validate JSON payloads against a schema in an API
- validate configuration files with JSON Schema
- validate user input in a browser form
- check JSON data structure in Node.js scripts
- validate data using JSON Type Definition RFC8927
- validate ESLint-style plugin configuration schemas
- generate fast reusable validators from schemas

## When to choose
- you need high-performance, standards-compliant JSON Schema validation in JavaScript
- you want declarative data validation without writing manual checks
- you need support for multiple JSON Schema drafts or JTD
- you validate schemas in Node.js, browser, or Electron apps

## When to avoid
- you need validation in a non-JavaScript language
- you only need simple ad-hoc checks that don't warrant a schema library
- you require draft-04 support without adding the separate ajv-draft-04 package

## Facets
- artifact type: library
- maturity: stable
- function: serialization, developer-tools
- domain: developer-tools, web-development, apis, backend, frontend
- platform: browser, cross-platform
- tags: -schema, -validation, schema-validator, -type-definition, rfc8927, data-validation, nodejs, electron, typescript

## Member repositories
- ajv-validator/ajv (main) score 81

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:07.745973+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:07:08.643811+00:00, confidence not recorded.
  - readme: https://github.com/ajv-validator/ajv (fetched 2026-08-28T04:11:07.745973+00:00, sha 78cf8ed0ec77)
  - homepage: https://ajv.js.org (fetched 2026-08-29T08:05:27.163545+00:00, sha 1c5873aaa63d)
  - site_page: https://ajv.js.org/guide/getting-started.html (fetched 2026-08-29T08:05:27.173065+00:00, sha 8cb30c7d6dcf)
  - site_page: https://ajv.js.org/faq.html (fetched 2026-08-29T08:05:27.175500+00:00, sha 23e6b923dcc9)
- Data as of 2026-08-30T08:39:29.467469+00:00.