Code Beautifier & Formatter 💻
Clean, format, and properly indent your messy JSON, HTML, or CSS code instantly — 100% in your browser.
Free Online Code Beautifier — Format JSON, HTML & CSS Instantly
Messy, minified, or unindented code is incredibly difficult to read and debug. Our free code beautifier helps developers, students, and designers instantly clean up JSON, HTML, and CSS code with proper indentation and structure — entirely inside your browser, with no code ever sent to a server.
Whether you have copied a minified JavaScript API response, received a poorly formatted HTML template, or need to quickly read a compressed CSS file, this free online code formatter gives you a readable, properly indented version in one click.
JSON Formatter & Validator
When you paste valid JSON, this tool uses JavaScript's built-in JSON.parse() to validate the structure and JSON.stringify() to reformat it with clean 2-space indentation. This means it also acts as a JSON validator — if your JSON has a syntax error (missing comma, unclosed bracket), the parser will catch it and the tool falls back to a general formatting pass so you can still see the approximate structure.
HTML Code Beautifier
For HTML, the tool splits all tags onto individual lines and applies nested indentation based on opening and closing tag detection. This is especially useful when you receive a single-line HTML template from a CMS export, an email builder, or a web scraper — turning it into a structured, readable format that you can edit and understand at a glance.
CSS Formatter
For CSS, the tool places each selector on its own line, indents all properties inside their rule blocks, and adds clean line breaks between rules. This is useful when working with minified stylesheets from third-party libraries or frameworks where all rules have been compressed into a single line for production.
Why Beautify Code?
- Easier Debugging: Properly indented code makes it far easier to spot missing brackets, unclosed tags, or incorrect nesting.
- Code Reviews: Readable code is essential when sharing work with a team or asking for help in forums.
- API Responses: JSON responses from APIs are often minified — beautifying them makes it easy to understand the data structure.
- Learning: Students and beginners can paste example code from tutorials and see its proper indented structure immediately.
A Quick Note on Privacy & Trust
This tool runs entirely in your browser. No code you paste is ever sent to a server, logged, or stored. This makes it safe to use with API keys, configuration files, database responses, and other sensitive code that you would not want transmitted over a network to a third-party server.
Frequently Asked Questions
What is a code beautifier and what does it do?
It takes messy, unindented, or minified code and reformats it with consistent indentation and line breaks so it is easier to read, debug, and maintain. This tool supports JSON, HTML, and CSS.
What types of code can this formatter handle?
JSON (including nested objects and arrays), HTML (including nested tags), and CSS (including multiple selectors and properties). It auto-detects JSON and applies strict parsing; HTML and CSS use a tag and rule splitting approach.
Is my code sent to a server when I use this tool?
No. Everything runs entirely in your browser using JavaScript. None of the code you paste is ever sent to or stored on any server — safe for sensitive files and API responses.
Why would I need to beautify minified code?
Minified code has all whitespace removed to reduce file size for production. While great for performance, it's nearly impossible to read or debug. A beautifier restores the readable structure.
Can I use this as a JSON formatter and validator?
Yes. When JSON is detected, the tool validates it using JSON.parse() and formats it with 2-space indentation using JSON.stringify(). If your JSON has a syntax error, the tool catches it and falls back to general formatting.
Does this tool work for CSS formatting too?
Yes. CSS is formatted with each rule on its own line and properties indented inside their selector blocks, making even large compressed stylesheets easy to read.
About This Tool
This Code Beautifier was built by the FreeImageTools team — web developers who work with JSON APIs, HTML templates, and CSS stylesheets daily. We built this tool because most free online code formatters either send your code to a remote server (a security risk for sensitive data), require you to select the language manually every time, or produce incorrect indentation for nested HTML structures. Our tool auto-detects JSON using strict parsing, applies tag-based splitting for HTML, and uses rule-block detection for CSS — covering the three formats developers most commonly need to clean up on the fly. The formatting logic is tested regularly — most recently in June 2026. Nothing you paste is ever transmitted outside your browser.