Joi
A schema-based validation library for JavaScript.
What it does
A schema-based validation library for JavaScript.
When it fits
Checking structured request payloads and configuration objects.
Other options in this category
- ArkType — Validating external data while keeping schema definitions close to static types.
- io-ts — Validating data at application boundaries in functional TypeScript code.
- Superstruct — Checking application input with small reusable data structures.
- T3 Env — Failing early when server or client configuration is missing or invalid.
- Yup — Defining form constraints and reusable object validation rules.
Source
Editorial overview reviewed on October 24, 2026. Follow the source for current setup, compatibility, and licensing.