# java-json-tools/json-schema-validator

A JSON Schema validation implementation in pure Java, which aims for correctness and performance, in that order

Repository: https://github.com/java-json-tools/json-schema-validator
Canonical: https://ross.abutalabs.com/products/json-schema-validator
Homepage: http://json-schema-validator.herokuapp.com/
Language: Java
License: NOASSERTION
License Family: other
Last push: 2024-07-17T13:20:56+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5546, "days_push": 777, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1644, forks 395 (observed 2026-08-28T04:05:16.173375+00:00)

## What it is
A pure Java implementation of JSON Schema validation supporting draft v4 (with hyperschema) and draft v3, focused on correctness and performance. It is available on Maven Central and works on Android.

## Use cases
- validate  documents against a  schema in java
- validate api request payloads against  schema draft v4
- validate  strings against a schema on android
- check  schema hyperschema syntax compliance
- add  schema validation to a jvm backend service

## When to choose
- you need a mature, correctness-focused JSON Schema validator on the JVM
- you need draft v4 and v3 support including hyperschema syntax
- you need a dependency-free pure Java validator that runs on Android
- you consume libraries from Maven Central or Gradle

## When to avoid
- you need support for newer JSON Schema drafts like 2019-09 or 2020-12
- you want a validator in a non-JVM language
- you need actively developed features beyond maintenance releases

## Facets
- artifact type: library
- maturity: maintenance
- function: testing, serialization
- domain: developer-tools, apis, backend
- platform: jvm, cross-platform
- tags: -schema, validation, schema-validation, pure-java, android

## Member repositories
- java-json-tools/json-schema-validator (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:16.173375+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 2026-08-30T03:45:49.992723+00:00, confidence not recorded.
  - readme: https://github.com/java-json-tools/json-schema-validator (fetched 2026-08-28T04:05:16.173375+00:00, sha 70e1fb52d789)
- Data as of 2026-08-30T08:39:29.467469+00:00.