HTML formatter

HTML Lint is the free online validator and reformatter tool for HTML ✅, a lightweight interchange format ✅. Copy and paste or directly type in the editor and let HTMLLint format and validate your HTML code ✅.

We don't store any tracking cookies 🍪 And we do not store any input data. Your code is your ownership, we just make it prettier for you ✅.

How to lint HTML

css-formatter parses and validates your CSS. We’re checking for industry standards. And this will improve readability of your code.

Why linting HTML code

Linting HTML source code improves readability for your fellow developers and for yourself. It becomes clear where the several sections, headings, paragraphs, forms and buttons are.

Tips & Tricks

  • If you want your HTML code to be clean. You can paste your whole script in the code section and let HTML Lint format your code.
  • You can format CSS if you paste your CSS between <style></style>. Or you can use to format your CSS.
  • You can format JS if you paste your Javascript between <script></script>. Or you can use to format your JavaScript.
  • You can format XML, simply copy and paste your in the code section above. Or you can use to format your XML.
  • You can format JSON at

Calculate and visualize Cumulative Layout Shift of your website

In the year 2021 Google introduced Core Wev Vitals. It’s a way of measuring a page’s health based on a number of factors like page speed, readability, structured data and cumulative layout shift. The layout shift in this instance could not be bigger than 20% of the page’s height. If it’s greater that 0.2 Google will penelize your website for it. To calculate and visualize the layout shift of your page visit