
ValidateHTML
Validate HTML, CSS, JSON, XML & more — instantly
Details
- Categories
- Developer ToolsSEO & Content Marketing
- Target Audience
- Backend DevelopersDevelopersDevOps Engineers
- Pricing
- Free
- Platforms
- Web
- Featured in
- Best Code Review Tools
- Alternative To
W3C Validator
JSONLintCCSS LintFFreeFormatter
About ValidateHTML
The problem: web validators are scattered. The W3C validator is slow and clunky. JSONLint only does JSON. CSS Lint is dead. Most tools look like they were built in 2003. ValidateHTML brings 13 essential validation and formatting tools into one clean, fast, free site — no account, no paywall, no rate limits. --- **Tools included** Validators: - HTML Validator (standards compliance + common errors) - HTML5 Validator - CSS Validator - JSON Validator - XML Validator - Open Graph tag checker - Meta tags analyzer - robots.txt validator - Accessibility checker - Page size analyzer Formatters: - HTML Formatter (beautify / minify) - JSON Formatter (pretty-print / compact) --- **Key features** - Quality Score 0–100 + Grade A–F on every tool - PDF export for every validation report - Paste code or enter a URL — your choice - Dark UI, fully responsive - No signup, no login, no limits --- **Why it's different** Faster and cleaner than the official W3C validator. More tools than any single-purpose validator. Consistent UX and scoring system across all 13 tools. Built with Next.js on Vercel — it's fast. Built for developers who want to ship clean, accessible, standards-compliant code without slowing down. --- Stack: Next.js · TypeScript · Tailwind CSS · Vercel
Product Insights
ValidateHTML integrates 13 distinct validation and formatting tools into a unified web interface, supporting HTML, CSS, JSON, and XML. This free platform provides immediate scoring and PDF reporting without requiring account registration or enforcing rate limits.
- Comprehensive suite including HTML5, CSS, JSON, XML, and Accessibility validators.
- Provides a standardized Quality Score (0-100) and Grade (A-F) across all tool categories.
- Supports both raw code input and URL-based validation for live site analysis.
- Completely free pricing model with no signup, paywalls, or usage restrictions.
Ideal for: Backend Developers, Developers, and DevOps Engineers can use this tool for code review and SEO optimization to ensure standards compliance and accessibility.
This platform serves as a modern alternative to tools such as the W3C Validator, Nu HTML Checker, JSONLint, CSS Lint, and FreeFormatter.
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Comments (1)
Validating HTML, CSS, JSON, XML and more instantly from one tool is super handy. Developers jump between multiple validators constantly and having them unified saves real time during code review.
Thanks @chaudharyarun5797! Exactly the pain, too many tabs open before every deploy. Built it to fix my own workflow. What validators would you love to see next?