Head-to-Head: Ajv vs ow Analysis


v8.12.0(9 months ago)

This package is actively maintained.Types definitions are bundled with the npm packageNumber of direct dependencies: 4Monthly npm downloads

Ajv is a popular JSON Schema validator used for data validation in JavaScript applications. It supports the latest JSON Schema draft compatible with many other validators including tv4, draft-js-validator, and z-schema. Ajv has a small and fast implementation, making it suitable for use in both frontend and backend applications. It also supports asynchronous validation and offers many features for generating custom errors and dialects.

Alternatives: tv4, Z-schema, jsonschema

Tags: json-schemavalidationjavascriptfrontendbackend


v1.1.1(8 months ago)

This package is actively maintained.The package doesn't have any types definitionsNumber of direct dependencies: 5Monthly npm downloads

OW is a powerful and flexible JavaScript library for validating and asserting the types and shapes of JavaScript values. It provides a simple and intuitive API for defining validation rules and checking if values meet those rules. OW supports various types of validations including primitive types, arrays, objects, functions, and more.

Alternatives: joi, yup, io-ts

Tags: javascriptvalidationassertiontypesshapes



Ajv is a widely used JSON Schema validator and has been around for a longer time. It has a large user base and is well-established in the JavaScript community. Ow, on the other hand, is a newer package and may not have the same level of popularity as Ajv.


Ow is a lightweight package with a small footprint, making it suitable for projects where size is a concern. Ajv, while not significantly larger, has a slightly larger codebase due to its more extensive feature set.


Ajv is primarily focused on JSON Schema validation and provides comprehensive support for JSON Schema specifications. It offers advanced features such as asynchronous validation, custom keywords, and schema compilation. Ow, on the other hand, is a general-purpose validation library that aims to provide a simple and expressive API for validating JavaScript values without the need for schemas.

Developer Experience

Ow provides a clean and intuitive API with a fluent syntax that allows for easy chaining of validation rules. It also provides descriptive error messages, making it easier to identify validation issues. Ajv has a more complex API due to its support for JSON Schema specifications, which may require a steeper learning curve for developers unfamiliar with JSON Schema.


Both Ajv and Ow can be easily integrated into JavaScript projects. Ajv has extensive support for JSON Schema specifications and can be used with various frameworks and tools. Ow, being a general-purpose validation library, can be used in any JavaScript project without any specific dependencies.


Both Ajv and Ow are actively maintained by their respective communities. Ajv has a larger user base and a longer history of development, which ensures ongoing maintenance and updates. Ow, being a newer package, may have a smaller community but is still actively maintained and receives updates.