ajv vs superstruct

ajv is downloaded 59.9× more often than superstruct (1,239,468,287 vs 20,701,143 per month), so it has the larger community and more answered questions online. superstruct ships 89% less gzipped JavaScript (3.4 kB vs 32.0 kB), which matters if bundle size is a priority. ajv has been updated more recently, a sign of more active maintenance.

Metricajvsuperstruct
Weekly downloads290,096,050✓4,952,034
Monthly downloads1,239,468,287✓20,701,143
GitHub stars14,721✓7,143
Minified size109.1 kB10.2 kB✓
Minified + gzipped32.0 kB3.4 kB✓
Dependencies40✓
Open issues342100✓
Last commit2026-05-12✓2024-10-01
Latest version8.20.02.0.2
LicenseMITMIT

When to choose which

ajv

The fastest JSON Schema validator.

Choose it when: You use the JSON Schema standard (e.g. OpenAPI payloads) and want maximum validation performance.

  • + Extremely fast
  • + JSON Schema standard
  • + Great for APIs
  • - JSON Schema, not TS-first
  • - Verbose schemas

superstruct

Lightweight, composable data validation.

Choose it when: Simple, composable validation with a small footprint when you don't need Zod's full feature set.

  • + Small & composable
  • + Type inference
  • - Sync only
  • - Smaller ecosystem

Feature comparison

Featureajvsuperstruct
Static type inferencePartial✓ Yes
Async validation✓ Yes✗ No
Standard Schema✗ No✗ No
API styleJSON SchemaComposable functional
Best forAPI payloadsLightweight needs

ajv

Another JSON Schema Validator

DetailsGitHubnpm

superstruct

A simple and composable way to validate data in JavaScript (and TypeScript).

DetailsGitHubnpm

Related comparisons

ajv vs zodsuperstruct vs zodajv vs yupsuperstruct vs yupajv vs joijoi vs superstructajv vs valibotsuperstruct vs valibot

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ajv vs superstruct downloads
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Data from npm, Bundlephobia and GitHub. Last updated 2026-06-02.