About this site

What it is

HTML Formatter Online is a free browser-based formatter, beautifier, minifier and validator for HTML. There is no account, no upload and no server-side processing. You paste markup, the JavaScript in your browser parses it, and you get the result back.

It exists because formatting HTML is a thing people need to do several times a week and almost never want to set up tooling for. If you are editing a project you own, use Prettier — it is better at this than any website can be. If you have a snippet, an export, a page you are debugging on a machine that is not yours, or a file you would rather not upload anywhere, that is what this is for.

How it is built

Static HTML and CSS, with about 500 lines of vanilla JavaScript doing the actual work. No framework, no build step, no analytics running on the tool itself.

The formatter is a real parser rather than a set of regular expressions. It tokenises the input, builds a tree, applies the same implicit-closing rules a browser applies, then prints the tree back out. That is why it survives markup with a > inside an attribute value, comments containing tags, and unclosed <li> elements — the cases that break naive tools.

Raw-text elements are treated as opaque. Whatever is inside <pre>, <textarea>, <script> and <style> comes back byte for byte.

The privacy position

Your markup is never transmitted. This is not a policy promise, it is an architectural fact — there is no endpoint to send it to. You can confirm it in thirty seconds: open your browser's developer tools, switch to the Network tab, paste something and press Format. Nothing is requested.

The site does serve third-party advertising, and ad networks set their own cookies. That is covered in detail in the privacy policy. The distinction worth understanding is that the advertising and the tool are entirely separate: the ad code never sees what is in the panels, because the panels' contents never leave the JavaScript running on your page.

What it costs

Nothing, and there is no plan for that to change. There is no premium tier being held back, no usage cap waiting to be hit and no account you will eventually be asked to create. Advertising covers the hosting.

Get in touch

Bug reports, feature requests, corrections to any of the guides, or a formatting case the parser gets wrong — all welcome at contact@htmlformatteronline.com. If you are reporting a bug, the input that triggered it is the single most useful thing you can include.