io-ts
A runtime type system for decoding and encoding data.
What it does
A runtime type system for decoding and encoding data.
When it fits
Validating data at application boundaries in functional TypeScript code.
Other options in this category
- ArkType — Validating external data while keeping schema definitions close to static types.
- Joi — Checking structured request payloads and configuration objects.
- 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.