Formatly
Runs in your browser

Format JSON, XML & HTML — fast, free and private

A modern online formatter, validator and beautifier for developers. Everything runs in your browser, so your data never leaves your device.

Format JSON Format XML Format HTML
No data leaves your browser Instant formatting Free · No sign-up
JSON

JSON Formatter

Format, validate, beautify and minify JSON. Lossless — preserves big numbers and key order.

Open JSON formatter →
XML

XML Formatter

Format, validate, beautify and minify XML. Keeps CDATA, comments and the XML declaration intact.

Open XML formatter →
HTML

HTML Formatter

Format, beautify and minify HTML. Safe handling of <pre>, <script> and <style> via js-beautify.

Open HTML formatter →

Why developers choose Formatly

Blazing fast

A purpose-built engine formats most documents instantly, with a Web Worker for very large files.

100% private

Everything runs in your browser. Your data is never uploaded, logged or stored.

Precise validation

Pinpoint errors with the exact line and column, plus a one-click jump to the problem.

Tree view

Explore JSON and XML as a collapsible tree to navigate deeply nested data with ease.

Format or minify

Beautify with 2/4-space or tab indentation, or compact to the smallest size in one click.

Clean & lightweight

A clean, modern, distraction-light interface with dark mode, system fonts and instant rendering.

Privacy by design

Most online formatters send whatever you paste to a remote server. Formatly does not. All parsing, formatting, validation and minification happen locally in your browser using JavaScript — there is no network request carrying your data, nothing is logged, and nothing is stored on our side.

That makes Formatly safe for sensitive payloads: API responses, configuration files, tokens, logs and proprietary markup. The only thing kept is your most recent input and your theme preference, saved in your own browser's local storage so the page is ready when you come back.

How it works

  1. Pick a tool — JSON, XML or HTML.
  2. Paste your code, drop a file, or load the built-in sample.
  3. Click Format to beautify, Minify to compact, or Validate to check for errors.
  4. Review the result with syntax highlighting or the tree view, then Copy or Download.

Frequently asked questions

Is Formatly free to use?
Yes. Every tool — the JSON, XML and HTML formatters, validators, beautifiers and minifiers — is completely free, with no sign-up and no usage limits.
Is my data private and secure?
Yes. Formatly runs 100% in your browser. Your code is never uploaded to a server, logged or stored anywhere — formatting happens locally on your device.
Which formats can I format and validate?
JSON, XML and HTML. Each has a dedicated page for formatting, beautifying, minifying and validating, with a collapsible tree view for JSON and XML.
Does Formatly work offline?
Once the page has loaded, formatting runs entirely on-device, so it keeps working even with a flaky connection. (The HTML beautifier loads a small module on first use.)
Do I need to install anything or create an account?
No. Formatly is a website — open it in any modern browser and start formatting. There is nothing to install and no account required.