# go-ozzo/ozzo-validation

An idiomatic Go (golang) validation package. Supports configurable and extensible validation rules (validators) using normal language constructs instead of error-prone struct tags.

Repository: https://github.com/go-ozzo/ozzo-validation
Canonical: https://ross.abutalabs.com/products/ozzo-validation
Language: Go
License: MIT
License Family: permissive
Topics: validation, golang, go, ozzo, validator
Last push: 2026-08-25T17:26:55+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 96, longevity 100
- inputs: {"age_days": 3724, "days_push": 8, "days_rel": 29, "gap_med": 0, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4129, forks 244 (observed 2026-08-28T04:08:36.073407+00:00)

## What it is
ozzo-validation is an idiomatic Go package for configurable and extensible data validation. It uses normal programming constructs instead of error-prone struct tags and ships with a rich set of built-in rules plus easy custom rule creation.

## Use cases
- validate request payloads in a Go REST API
- validate struct fields in Go without struct tags
- validate strings, slices, maps, and custom types in Go
- create custom validation rules in Go
- translate validation error messages and codes

## When to choose
- you want code-based, type-safe validation in Go instead of struct tags
- you need extensible rules and custom Validatable types
- you need localized or well-formatted validation errors

## When to avoid
- you prefer declarative struct-tag validation like go-playground/validator
- you are not working in Go

## Facets
- artifact type: library
- maturity: stable
- function: form-handling, developer-tools
- domain: backend, web-development, developer-tools
- platform: go, cross-platform
- tags: validation, data-validation, struct-validation, validators, golang-library

## Member repositories
- go-ozzo/ozzo-validation (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:36.073407+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 2026-08-29T18:23:03.565085+00:00, confidence not recorded.
  - readme: https://github.com/go-ozzo/ozzo-validation (fetched 2026-08-28T04:08:36.073407+00:00, sha 746897cd0c4e)
- Data as of 2026-08-30T08:39:29.467469+00:00.