Web development validation and testing tools
Summary
This article lists online tools for validating and testing web projects, ensuring compliance with standards, accessibility, and security. Each tool is categorized by purpose and linked for direct use.
Introduction #
Validating and testing your code ensures it meets standards, functions correctly, and remains accessible.
This article lists online tools for checking Hypertext Markup Language (HTML), Cascading Style Sheets (CSS), accessibility (a11y), security, and other web technologies. Each tool is categorized by purpose and linked for direct use.
HTML validation #
Nu HTML Checker
A modern HTML validator that checks markup for compliance with W3C standards and accessibility best practices. Published by World Wide Web Consortium (W3C).Schema Markup Validator
Validates structured data markup (Schema.org) to ensure proper implementation for search engines and rich snippets. Published by Schema.org.Rich Results Test
Rich results are experiences on Google surfaces, such as Search, that go beyond the standard blue link. Rich results can include carousels, images, or other non-textual elements. Published by Google.
CSS validation #
- CSS Validator
Validates CSS code against W3C standards, identifying syntax errors and non-standard usage. Published by World Wide Web Consortium (W3C).
Accessibility (a11y) testing #
Nu HTML Checker
A modern HTML validator that checks markup for compliance with W3C standards and accessibility best practices. Published by World Wide Web Consortium (W3C).WAVE Web Accessibility Evaluation Tool
Suite of evaluation tools that helps authors make their web content more accessible to individuals with disabilities. Published by Web Accessibility In Mind (WebAIM).Mauve++
Suite of evaluation tools that helps authors make their web content more accessible to individuals with disabilities. Published by Human Interfaces in Information System Lab at the Institute of Information Science and Technologies - National Research Council.
Security and privacy testing #
HTTP Observatory
The HTTP Observatory enhances web security by analyzing compliance with best security practices. Published by Mozilla Developer Network (MDN).Webbkoll
Webbkoll helps you check what data-protecting measures a site has taken to help you exercise control over your privacy. Published by 5th of July Foundation (5july).
Internationalization (i18n) checking #
- Internationalization Checker
Analyzes web content for internationalization (i18n) issues, helping ensure proper language and character encoding support. Published by World Wide Web Consortium (W3C).
JavaScript validation #
JSLint
A strict JavaScript code quality tool that enforces coding standards and detects potential errors. Published by JSLint.JSHint
Code analysis tool for JavaScript that detects errors and potential problems in your code while enforcing coding conventions. Published by JSHint.Debuggex
Debuggex is an interactive online tool for visualizing and testing JavaScript regular expressions (regex) and finite automata with real-time matching and debugging. Published by Debuggex.RegExr
Regexr is a web-based tool for creating, testing, and learning regular expressions with real-time feedback, syntax highlighting, and reference guides. Published by RegExr.
Structured data and feed validators #
RDF Validator
Checks RDF (Resource Description Framework) documents for correct syntax and semantic structure. Published by World Wide Web Consortium (W3C).RSS & Atom Feed Validator
Validates RSS and Atom feeds to ensure proper formatting and compatibility with feed readers. Published by World Wide Web Consortium (W3C).Schema Markup Validator
Validates structured data markup (Schema.org) to ensure proper implementation for search engines and rich snippets. Published by Schema.org.TOML Lint
TOML Lint is a free online tool that validates and formats TOML (Tom’s Obvious, Minimal Language) files. Published by Greg Schofield.
FAQ's #
Most common questions and brief, easy-to-understand answers on the topic:
What is the purpose of validation tools in web development?
Validation tools help ensure that your HTML, CSS, and other assets follow official specifications, improving site reliability and cross-browser compatibility.
What is the purpose of the Nu HTML Checker?
The Nu HTML Checker validates Hypertext Markup Language (HTML) for compliance with W3C standards and accessibility guidelines.
Is privacy evaluation covered by any of these tools?
Yes. Webbkoll and HTTP Observatory analyze privacy-related headers and other site behaviors.
How does the WAVE Web Accessibility Evaluation Tool help?
The WAVE tool identifies accessibility issues in web content, ensuring compliance with Web Content Accessibility Guidelines (WCAG).
Can the CSS Validator detect syntax errors?
Yes, the CSS Validator checks Cascading Style Sheets (CSS) for syntax errors and non-standard usage.
What does i18n stand for in web development?
i18n is short for internationalization, referring to the adaptation of web content for different languages and regions.
Is the Schema Markup Validator useful for search engines?
Yes, the Schema Markup Validator ensures structured data is correctly implemented for search engine rich results.
Further readings #
Sources and recommended, further resources on the topic:
Author
Jonas Jared Jacek (J15k)
Jonas works as project manager, web designer, and web developer since 2001. On top of that, he is a Linux system administrator with a broad interest in things related to programming, architecture, and design. See: https://www.j15k.com/License
Web development validation and testing tools by Jonas Jared Jacek is licensed under CC BY-SA 4.0.
This license requires that reusers give credit to the creator. It allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, for noncommercial purposes only. To give credit, provide a link back to the original source, the author, and the license e.g. like this:
<p xmlns:cc="http://creativecommons.org/ns#" xmlns:dct="http://purl.org/dc/terms/"><a property="dct:title" rel="cc:attributionURL" href="https://www.ditig.com/web-development-validation-and-testing-tools">Web development validation and testing tools</a> by <a rel="cc:attributionURL dct:creator" property="cc:attributionName" href="https://www.j15k.com/">Jonas Jared Jacek</a> is licensed under <a href="https://creativecommons.org/licenses/by-sa/4.0/" target="_blank" rel="license noopener noreferrer">CC BY-SA 4.0</a>.</p>For more information see the Ditig legal page.
