ajv VS joi

Compare ajv vs joi and see what are their differences.

ajv

The fastest JSON schema Validator. Supports JSON Schema draft-04/06/07/2019-09/2020-12 and JSON Type Definition (RFC8927) (by ajv-validator)

joi

The most powerful data validation library for JS [Moved to: https://github.com/sideway/joi] (by hapijs)
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ajv joi
60 8
13,353 16,531
1.1% -
6.0 6.7
6 days ago about 3 years ago
TypeScript JavaScript
MIT License GNU General Public License v3.0 or later
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.

ajv

Posts with mentions or reviews of ajv. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2024-04-07.
  • Popular Libraries For Building Type-safe Web Application APIs
    6 projects | dev.to | 7 Apr 2024
    Ajv’s documentation is available here.
  • 6 Reasons why JSON Schema is worth your time
    5 projects | dev.to | 3 Oct 2023
    In the JavaScript ecosystem you can use the excellent AJV package to validate any JavaScript object against a JSON schema. This is especially useful to ensure that API contracts are maintained when communicating with other services.
  • Migrate Your Express Application to Fastify
    12 projects | dev.to | 5 Jul 2023
    Since Fastify supports schema validation with Ajv, the validate module is no longer required on the /shorten route, and we can specify the JSON schema directly on the route. The controllers for both routes will largely remain the same, except that the res parameter is renamed to reply as before:
  • Has anybody used Typia library?
    3 projects | /r/typescript | 27 Jun 2023
    There's a ton of schema validators out there and most devs have their personal favorite. Mine was zod and is now typebox + ajv.
  • Accept only specific keys in JSON or form-data format in express?
    1 project | /r/node | 16 Jun 2023
    Good validator library: https://www.npmjs.com/package/ajv
  • Advanced Fastify: Hooks, Middleware, and Decorators
    4 projects | dev.to | 31 May 2023
    Fastify uses JSON schema to define the validation rules for each route's input payload, which includes the request body, query string, parameters, and headers. The JSON schema is a standard format for defining the structure and constraints of JSON data, and Fastify uses Ajv, one of the fastest and most efficient JSON schema validators available.
  • Getting Started with Fastify for Node.js
    4 projects | dev.to | 5 May 2023
    In Fastify, JSON schema validation is a built-in feature that allows you to validate the payload of incoming requests before the handler function is executed. This ensures that incoming data is in the expected format and meets the required criteria for your business logic. Fastify's JSON schema validation is powered by the Ajv library, a fast and efficient JSON schema validator.
  • How can we map data from JSON to typescript object efficiently?
    4 projects | /r/reactjs | 30 Apr 2023
    I think you're looking for a json schema validator like Ajv or Zod.
  • 5 useful JSON tools to improve your productivity
    4 projects | dev.to | 11 Apr 2023
    We can use JSON Schema to validate that our data adheres to a specific structure. Ajv is one popular validator tool for JavaScript applications that allows us to create a schema and then validate JSON against that schema. Here's an example of using Ajv to validate one of the above JSON examples against a schema:
  • Ask HN: JSON API object type definitions and validation in 2023?
    2 projects | news.ycombinator.com | 23 Mar 2023
    Hey HN,

    We're designing a new system and have been kicking the can about JSON object definitions and validation. Soon we need to settle on a system to validate API request bodies and provide helpful error messages.

    In the past, I've used JSON Schema ( https://json-schema.org/ ) to define definitions and ajv ( https://ajv.js.org/ ) to validate, but it's a bit verbose and ajv validation errors are more cryptic than I'd like to deal with.

    TypeSchema looks interesting. It seems solid (and perhaps stable?), but development hasn't been active for 2 years. It also looks like we'd still need to generate JSON Schema and choose a validation library

    Anyway, I'm very curious how others are approaching this problem. How do you organize and generate validations for your type definitions? What libraries do you use to validate and provide human readable error messages?

    Thank you!

joi

Posts with mentions or reviews of joi. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2023-10-29.
  • Reading Docusaurus code
    2 projects | dev.to | 29 Oct 2023
    Code in Docusaurus This module validates and processes frontmatter objects by using Joi library for the data validation.
  • Serverless, the Intersection of Technology and People
    2 projects | dev.to | 8 Apr 2023
    Once you've leaped into thinking as a serverless problem solver, it makes a lot of sense to standardize some tooling and frameworks. The old adage right tool for the job is what I like about this layer of the pyramid. For instance, if a problem requires flexibility in data and your team enjoys validating schema with Joi then you might use TypeScript with a Node.js runtime with your lambdas. If you prefer the developer experience and small footprint and simplicity of Go then use the Go 1.x runtime. You might find you don't need "compute" at all, so using intrinsic functions in State Machines might be plenty.
  • Boilerplate for Typescript-Express with sequelize ORM
    14 projects | dev.to | 8 Nov 2022
    Validation: request data validation using Joi
  • In contact us page users can submit request to contact only if they have an account?
    1 project | /r/webdev | 4 Nov 2022
    I'm using Joi on my server to validate form input, do you think I still need honeypot fields? It sounds like it might be worth looking into IP rate limiting as well, I don't think Joi can help with that.
  • Minimal and fast runtime API payload sanitiser and error message handling
    7 projects | /r/typescript | 20 Oct 2021
    What does your library provide that others don't? For example: https://github.com/colinhacks/zodhttps://github.com/hapijs/joihttps://github.com/jquense/yuphttps://github.com/gcanti/io-tshttps://github.com/pelotom/runtypeshttps://github.com/sindresorhus/ow
  • JSON and scehama validator libraries for Node
    5 projects | dev.to | 22 Jul 2021
    Yup's API is heavily inspired by Joi, but leaner and built with client-side validation as its primary use-case. Yup separates the parsing and validating functions into separate steps. cast() transforms data while validate checks that the input is the correct shape. Each can be performed together (such as HTML form validation) or seperately (such as deserializing trusted data from APIs).
  • Build quality forms with React 🚀
    4 projects | dev.to | 16 Jun 2021
    Yup is a Javascript object schema validator: it lets you define a schema to describe how a valid object should look like, and allows you to validate an object using this schema. If you know Joi, Yup is heavily inspired by it, except it relies on client-side validation as its primary use-case.
  • Authentication and Authorisation 101
    2 projects | dev.to | 16 Jan 2021
    Again a widely used open source validation library like Joi can help you easily create schemas and transform the data into safe objects.

What are some alternatives?

When comparing ajv and joi you can also consider the following projects:

joi - The most powerful data validation library for JS [Moved to: https://github.com/hapijs/joi]

zod - TypeScript-first schema validation with static type inference

Yup - Dead simple Object schema validation

react-hook-form - 📋 React Hooks for form state management and validation (Web + React Native)

tv4 - Tiny Validator for JSON Schema v4

runtypes - Runtime validation for static types

typebox - Json Schema Type Builder with Static Type Resolution for TypeScript

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

class-validator - Decorator-based property validation for classes.

ow - Function argument validation for humans