10 Best Node.JS Data Validation Libraries to Keep Data Clean

Node.js is one of the most popular JavaScript runtime environments that allows developers to run JavaScript code outside a browser environment. 

Node.js has a large collection of modules/libraries that can be installed via a package manager like NPM or Yarn. These libraries perform different functions ranging from authentication, processing images & files, testing, running tasks, and logging, among other functions. 

Data validation libraries are among the most useful in the Node.js ecosystem. Data validation is the process of checking the accuracy and quality of source data before using it. 

A data validation library in Node.js is a module or software component that helps developers ensure the correctness and integrity of data within their applications. Such libraries provide functions and tools that perform data checks, provide validation rules and handle errors within an application. 

Node.js data validation libraries serve the following purposes;

• Define validation rules: Data validation libraries provide a configuration mechanism or flexible syntax specifying the expected structure of the input data. Such a setting makes it easy for developers to enforce certain rules before processing data. 
• Make it easy to reuse code: As your application increases in size, you may write the same code repeatedly. Data validation libraries in Node.js have modular code blocks that you can reuse with different components in your application.
• It makes its development more efficient: A library comes with a boilerplate code you can edit to suit your needs. Thus, you don’t have to write everything from scratch, which gives you more time to focus on the functionality of your application. 
• Improves data integrity: You can ensure the consistency and integrity of the data you process when you have a validation library. When you validate data, you ensure that invalid data that may cause security vulnerabilities or logical errors is not processed. 
• Help comply with regulations: Certain industries require that the data meets certain conditions before processing. A Data validation library can inspect such datasets to ensure compliance. 
• Helps keep the apps secure: Some hackers send malicious code when they want to hack into systems. A data validation tool can check if the inputs do not threaten the data quality or performance of the app. There also exist various tools for securing Node.js applications against various attacks. 

Now that you understand the importance of Node.js validation libraries and how they work, we can review some of the best.

VineJS

VineJS is a Node.js form validation library. With this library, you can validate the HTTP request body in your application’s backend. It exists as an ESM package that you can install using package managers such as NPM or Yarn. However, it is not available for the CommonJS module system.

Key features 

• Validates JSON payloads and form data: You will experience some quirks when serializing an HTML form to a JSON object or FormData. Luckily, VineJS natively handles such quirks under the hood, reducing your manual intervention. 
• Extensive suite of validation rules: There are 12 schema types and more than 50 validation rules you can apply when using this library. 
• Extensible: If the available rules and schema types don’t cover your needs, you can add custom schema types and rules to this library. 
• Supports custom error messages: You can get personalized responses by defining custom error messages in VineJS. 

Express-validator

Express-validator is a collection of express.js middlewares that wraps a set of sanitizers and validators offered by validator.js. You can combine these middlewares in different ways to sanitize and validate your express requests. This library also offers tools that determine if requests are valid and which data is matched to your validators. 

Key features 

• Offer several validation chains: We use functions such as query(), param(), and body() to create validation chains. These validation chains act as middleware and can be passed to any express.js route handler. 
• Customizable: A custom validator takes information about a field and a value that determines the validity. For instance, you can have a custom validator that checks if an email is in use. 
• Supports manual validation: You can run manual validations by providing your own middleware or route handler. 

Node Input Validator 

Node Input Validator is a Node.js validation library. You can also extend the rules contained in this library through custom rules. 

Key features

• Easy to use: Install the package using NPM to get started. You can use its detailed documentation and validate your inputs. 
• Different use cases: You can use Node Input Validator with plain JavaScript, express.js or async-await function. 
• Different validation types: You can use this library with objects or arrays in your Node.js project. 
• Custom messages: You can customize the error messages that the validator returns in case of an error. You can also add these error messages in various languages. 

Joi

Joi is a JavaScript validation library that allows you to describe your data using readable, simple and intuitive language. 

Key features 

• Several modules to choose from: You can validate an address such as a domain or email address, a formula, a date or, a pinpoint using Joi. 
• Online playground: You can test your data on the sandbox before you add this library to your Node.js project. 
• Detailed API: Joi’s has well-detailed API with complete examples to ensure you get the best out of this library. 

Schema-Inspector

Schema-Inspector is a JS tool for sanitizing and validating objects. This package is scalable as it allows asynchronous and synchronous calls and works both on the server and client side. 

Key features

• Supports different validation types: You can use Schema-Inspector with an array of strings or a string. You can also check property type. 
• Many sanitizations are available: This module allows you to sanitize data based on type, def, rules, optional, min & max, properties, and items…. etc. 
• Supports custom fields: You can use custom fields in a punctual case, a context, or an extension. 

Validate.js

Validate.js offers a declarative way of validating JS objects. This library is fit for production as it is unit tested with 100% code coverage. You install Validate.js through a package manager or add it to your components through a CDN link. 

Key features 

• Multiplatform: You can use Validate.js on Node.js or modern browsers such as Safari and Google Chrome. 
• Several validation functions are available: You can use different validation functions depending on your needs. Examples include Async validation, Nested validation, Single value validation, Error formatting, and Default options. 
• Several validation types are available: You can validate different objects such as Date, Length, Type, URL, email, and format. 
• Supports custom validation: You can write your own validator by adding to the validate.validators object.

Validator.js 

Validator.js is a library of string validators and sanitizers. You can install the package using a package manager like NPM or Bower or add it to your project through a CDN link. 

Key features 

• Available on both the client and server side: You can use Validator.js on the server side for both ES6 and non-ES6 JavaScript. 
• Only available for strings: Using this tool, you cannot sanitize or validate any other input apart from a string. 
• Variety of validators: This library has over 20 validators that check different parameters. 

Zod 

Zod is a TypeScript-first validation and schema declaration library. This library seeks to eliminate duplicate type declarations. Zod is a tiny package that is only 8kb minified + zipped. 

Key features 

• Extensive API library: You can use different APIs depending on your goal. Examples include koa-zod-router, tapiduck, domain functions, and zod-endpoints, to mention a few. 
• Multiplatform: Zod works perfectly in Node.js and most modern browsers. 
• Supports multiple languages: You can use Zod with plain JavaScript and TypeScript. 

MongooseJS

Mongoose is an Object Data Modelling library for MongoDB and Node.js. Validations in Mongoose are middlewares defined in the schema type. 

Key features 

• Comes with built-in validators: They fall under either numbers or strings. Each of these validators has several categories. 
• Supports manual validation: Use either doc.validateSync() or doc.validate to run manual validators. 
• Validations are customizable: You can run custom validations on Mongoose to suit certain scenarios. 
• Custom error messages: Mongoose allows you to configure the error message to be displayed on individual validators. 

Yup

Yup is a JavaScript schema builder for runtime value parsing and validation. You only need to define a schema, transform a value to match, and assert an existing value’s shape. 

Key features

• Expressive schema interface: Yup provides a way to represent, query, or manipulate data using a schema capturing semantic information or intricate relationships. 
• Async validation built-in: Async validation refers to a situation whereby validation does not block other processes as it goes on. It suits situations where the validation process involves time-consuming tasks. 
• Comprehensive error details: Yup returns comprehensive error details that make debugging easy. 
• TypeScript support: You can ensure that the schema implements a type correctly when using the Yup library. 

Conclusion

Node.js has a big ecosystem comprising libraries and packages with different functions. There is something for everyone, irrespective of whether you are looking for validation packages, productivity packages or charting libraries. 

You know, have a collection of data validation tools to select from. The choice of a data validation tool will depend on the nature of the data you want to validate and the ease of use.