html-validate
Advanced tools
html-validate is a powerful and highly configurable HTML linter that helps developers ensure their HTML code adheres to best practices and standards. It can catch common mistakes, enforce coding standards, and improve the overall quality of HTML code.
Basic HTML Validation
This feature allows you to validate a string of HTML code. The example demonstrates how to validate a simple HTML string and log the validation report, which will include any errors or warnings found in the HTML.
const HtmlValidate = require('html-validate');
const htmlvalidate = new HtmlValidate();
const report = htmlvalidate.validateString('<div><p>Unclosed tag</div>');
console.log(report);Custom Rule Configuration
This feature allows you to configure custom rules for validation. The example shows how to set up rules to flag inline styles as errors and duplicate IDs as warnings.
const HtmlValidate = require('html-validate');
const htmlvalidate = new HtmlValidate({
rules: {
'no-inline-style': 'error',
'no-dup-id': 'warn'
}
});
const report = htmlvalidate.validateString('<div id="test" style="color: red;"></div>');
console.log(report);Integration with Build Tools
This feature demonstrates how to integrate html-validate with build tools like Grunt. The example shows a Grunt configuration that validates all HTML files in the 'src' directory.
module.exports = function(grunt) {
grunt.initConfig({
htmlvalidate: {
options: {},
src: ['src/**/*.html']
}
});
grunt.loadNpmTasks('grunt-html-validate');
grunt.registerTask('default', ['htmlvalidate']);
};eslint-plugin-html is an ESLint plugin that allows you to lint and fix inline scripts contained in HTML files. It integrates with ESLint, providing a way to enforce JavaScript coding standards within HTML files. Compared to html-validate, it focuses more on JavaScript within HTML rather than HTML structure itself.
htmlhint is another HTML linter that helps you detect errors and potential issues in your HTML code. It is similar to html-validate but offers a different set of rules and configurations. htmlhint is known for its simplicity and ease of use, making it a good alternative for basic HTML linting needs.
stylelint is a modern linter that helps you enforce consistent conventions and avoid errors in your stylesheets. While it primarily focuses on CSS, it can be configured to lint inline styles within HTML files. Compared to html-validate, stylelint is more specialized in CSS linting.
Offline HTML5 validator. Validates either a full document or a smaller (incomplete) template, e.g. from an AngularJS or Vue.js component.
Read the full documentation at https://html-validate.org/
npm install -g html-validate
html-validate [OPTIONS] [FILENAME..] [DIR..]
Create .htmlvalidate.json:
{
"extends": [
"html-validate:recommended"
],
"rules": {
"close-order": "error",
"void": ["warn", {"style": "omit"}]
}
}
<p>
<button>Click me!</button>
<div id="show-me">
Lorem ipsum
</div>
</p>
1:1 error Element <p> is implicitly closed by adjacent <div> no-implicit-close
2:2 error Button is missing type attribute button-type
6:4 error Unexpected close-tag, expected opening tag close-order
The library comes in four flavours:
dist/cjs/index.js)dist/cjs/browser.js)dist/es/index.js)dist/es/browser.js)The browser bundle contains a slimmed version without CLI and NodeJS dependencies.
/* automatically determine build based on `browser` export condition */
import { ... } from "html-validate";
/* explicitly use nodejs bundle */
import { ... } from "html-validate/node";
/* explicitly use browser bundle */
import { ... } from "html-validate/browser";
See running in browser for details about getting HTML-Validate running in a browser environment.
Testing is done using jest.
npm test
or call jest directly.
Some tests are autogenerated from documentation examples, use npm run docs to build those before running.
Linting is done using ESLint.
npm run eslint
or call eslint directly.
npm run build
To build documentation use:
npm run docs
The documentation can be served locally using:
npm start
FAQs
Offline html5 validator
The npm package html-validate receives a total of 221,194 weekly downloads. As such, html-validate popularity was classified as popular.
We found that html-validate demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
ECMAScript 2025 introduces Iterator Helpers, Set methods, JSON modules, and more in its latest spec update approved by Ecma in June 2025.
Security News
A new Node.js homepage button linking to paid support for EOL versions has sparked a heated discussion among contributors and the wider community.
Research
North Korean threat actors linked to the Contagious Interview campaign return with 35 new malicious npm packages using a stealthy multi-stage malware loader.