Code Formatters — 9 Free Online Tools
9 free online code formatters. No signup required.
Format, validate, and beautify code in any language. Our free online formatters support JSON, HTML, SQL, CSS, YAML, and more. All processing happens in your browser - your code never leaves your device.
Need a JSON formatter online or an image compressor free? DevTools Hub has both, plus 279 free online developer tools that run entirely in your browser. Code Formatters are free online developer tools you can use instantly — no signup, no upload, 100% private. Popular free tools in this category include a free online JSON formatter and validator, an HTML formatter and beautifier, a SQL formatter, or a CSS formatter and minifier — all free to use online, no signup required. DevTools Hub is a collection of 279 free online developer tools that run entirely in your browser — no signup, no upload, no watermark. Popular tools across the whole site include a free JSON formatter online, a free image compressor free, a free online video compressor, and a free online calculator.
CSS Formatter & Validator - Beautify & Minify CSS Online
Free online CSS formatter and validator. Beautify messy CSS, minify for production, fix syntax errors. Instant results, no signup required.
Free YAML Validator - Validate & Format YAML Online
Free YAML validator and formatter. Validate YAML syntax, fix errors with line numbers, and format YAML for better readability. No signup required.
HTML Formatter - Format & Beautify HTML
Free HTML formatter. Format, prettify and beautify HTML code with proper indentation and validation.
JS Formatter & Beautifier - JavaScript Code Beautify Online
Free JavaScript formatter and beautifier. Beautify messy JS, minify for production, validate syntax. No signup, 100% private browser processing. AI cannot format code - we use deterministic js-beautify engine.
JSON Diff - Compare JSON Documents Online
Free JSON diff tool. Compare two JSON documents and see differences instantly. Highlights added, removed, and modified values. 100% private.
JSON Formatter - Format & Validate JSON
Free JSON formatter. Format, minify, beautify JSON and convert to YAML with syntax error detection.
JSON Schema Validator - Validate JSON Against Schema Online
Free JSON Schema validator. Validate JSON data against Draft-07, 2019-09, and 2020-12 schemas. Detailed error paths with JSON Pointer, all-errors mode, 100% private browser. AI cannot validate JSON against schema - we do.
SQL Formatter - Format & Beautify SQL
Free SQL formatter. Format and beautify SQL queries with proper indentation. Supports MySQL, PostgreSQL, SQLite.
XML Formatter - Format, Validate & Beautify XML Online
Free XML formatter and validator. Format, beautify, minify XML, convert to JSON, and validate well-formedness. Browser-based, no signup, 100% private.
Frequently Asked Questions
4 Q&AWhich languages and formats are supported?
Seven formatters cover JSON, HTML, CSS, SQL, YAML, XML, and JSON Schema (Draft-07, 2019-09, 2020-12). All run in the browser; no code is uploaded.What is the difference between beautify and minify?
Beautify adds consistent indentation and line breaks to make code human-readable. Minify removes whitespace, comments, and optional tokens to shrink the file size for production. Most formatters offer both modes.How large a file can I format?
In practice files up to several megabytes format instantly because the work is done in the browser. Files larger than that may slow down the page or hit browser memory limits; for very large files use a CLI tool.Is my code sent to a server?
No. The formatters are pure JavaScript that run locally in your browser. Your code, schemas, and data never leave your device.How to Use These Code Formatter Tools
guideEvery code formatter tool below runs entirely in your browser — no signup, no upload, no watermark. To find a specific tool, type a name, keyword, or scenario into the search box and the list filters instantly. Popular code formatter tools are linked in the summary at the top; click any card or link to open the tool and follow the on-screen instructions. Hover any tool card to read its full description, then click its name or button to open it.