Best TypeScript validation libraries
Libraries that check data at runtime, from form input to API payloads. ajv leads with about 518M real installs a week, followed by zod with about 453M.
| package | real installs / week | npm / week | noise | last release | confidence |
|---|---|---|---|---|---|
| 1. ajvAnother JSON Schema Validator | 518M | 518,007,029 | under 1% | Apr 2026 | high |
| 2. zodTypeScript-first schema declaration and validation library with static type inference | 453M | 453,207,139 | under 1% | Oct 2026 | high |
| 3. joiObject schema validation | 34.5M | 34,493,196 | under 1% | Nov 2026 | high |
| 4. valibotThe modular and type safe schema library for validating structural data | 32M | 31,975,379 | under 1% | Sep 2026 | high |
| 5. class-validatorDecorator-based property validation for classes. | 17M | 17,035,268 | under 1% | Feb 2026 | high |
| 6. yupDead simple Object schema validation | 16.4M | 16,369,893 | under 1% | Sep 2025 | high |
| 7. superstructA simple and composable way to validate data in JavaScript (and TypeScript). | 9.64M–9.65M | 9,646,688 | under 1% | Jul 2024 | high |
| 8. arktypeTypeScript's 1:1 validator, optimized from editor to runtime | 2.84M | 2,842,220 | under 1% | Oct 2026 | high |
Ranked by real installs. That measures use, not quality: read the notes below before choosing. Mirror spikes and crawlers removed. CI and dependency installs still count, so this is not a head count. Noise: the share of npm's count that mirror spikes and crawlers account for. What remains still includes CI and dependency installs. Rows are refreshed in rotation, the oldest here on Nov 6, 2026.
How do they differ?
Zod infers TypeScript types from its schemas. Valibot has a similar idea with a modular design for small bundles. Yup and Joi are older, and Joi is mostly used on the server. Ajv validates JSON Schema, which helps when a schema is shared across languages. class-validator uses decorators and is common with NestJS.