Code Formatter
Format, validate and minify JSON, CSS, HTML, SQL and JavaScript. Real-time output. Free, private, no upload.
Input
Output
Output will appear here
About Code Formatter
Poorly formatted code is harder to read, harder to debug, and harder to review. Whether you receive minified output from an API, auto-generated markup from a CMS, or disorganized SQL from a legacy system, reformatting it by hand wastes time. Our Code Formatter handles JSON, CSS, HTML, SQL, and JavaScript with configurable indentation and instant output.
For JSON specifically, the formatter also validates the structure and reports syntax errors with exact line and character positions — essential when debugging an API response or configuration file that is failing to parse. Minified JSON from production systems often contains subtle errors (trailing commas, unquoted keys) that only become visible when formatted with proper line breaks.
All formatting runs locally in your browser. No code, credentials, database queries, or proprietary business logic is ever transmitted to a server. This makes it safe to format sensitive configuration files, internal SQL queries, or company source code that should not leave your device.
How to Use Code Formatter
- 1Paste your code into the input field, or click "Upload File" to load a code file directly.
- 2Select the language from the dropdown — JSON, CSS, HTML, SQL, or JavaScript.
- 3Choose your indentation style (2 spaces, 4 spaces, or tabs) to match your project's conventions.
- 4Click "Format" to beautify the code and display the result in the output panel.
- 5For JSON, the validator runs automatically and highlights any syntax errors before formatting.
- 6Click "Copy" to copy the formatted output or "Download" to save as a file.
Use Cases
- →Beautify minified JSON from an API response for readable debugging
- →Format and validate JSON configuration files to catch syntax errors before deployment
- →Clean up auto-generated HTML or CSS before submitting code for review
- →Reformat SQL queries for readability before adding to documentation or a README
- →Quickly pretty-print JavaScript received from a third-party snippet or library
- →Validate JSON structure in configuration files, environment variable files, or API payloads
Tips
- ✓JSON validation runs automatically — the formatter shows the exact line and character of any error
- ✓Choose 2-space indentation for JavaScript/JSON and 4-space for Python-style projects
- ✓For very large files (multi-MB JSON exports), processing takes a few seconds — all in your browser
- ✓Use Tab size instead of spaces if your project uses .editorconfig with tab-based indentation
- ✓After formatting, use Ctrl+F in the output panel to search for specific keys or values
- ✓The Code Minifier tool does the reverse — use it to compress formatted code for production
Frequently Asked Questions
The formatter supports JSON, CSS, HTML, SQL and JavaScript. Each language has its own tab with specific actions — JSON includes validation with error line detection, SQL formats keywords in uppercase.
As you type, the formatter processes your code automatically after a 500ms pause. You can also switch between Format, Minify, and Validate modes at any time — the output updates instantly.
If your JSON has a syntax error, the output panel shows the exact error message and the line number where the error was found.
Format adds indentation and line breaks to make code readable. Minify removes all unnecessary whitespace and comments to reduce file size. Both preserve the code's behavior.
The SQL formatter automatically indents your queries, converts all SQL keywords (SELECT, FROM, WHERE, JOIN, etc.) to uppercase, and adds line breaks between clauses.
No. All formatting, validation and minification happens entirely in your browser using JavaScript. Your code never leaves your device.