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Free Online Developer Tools

CSS, JSON, regex, HTTP codes and developer utilities — 22 tools

JSON Formatter

Format, minify and validate JSON

Regex Tester

Test regular expressions with match highlighting

CSS Minifier

Minify and format CSS code

JS Beautifier

Format and minify JavaScript

HTML Formatter

Format and validate HTML code

SQL Formatter

Format SQL queries

Cron Generator

Visual cron expression generator

HTTP Status Codes

HTTP status codes reference with descriptions

MIME Types

MIME types reference by file extension

Flexbox Playground

Interactive playground for learning CSS Flexbox

CSS Grid Playground

Interactive playground for CSS Grid Layout

Diff Checker

Compare two code snippets with highlighted differences

JWT Decoder

Decode and verify JWT tokens

JSON to CSV Converter

Convert between JSON and CSV formats with nested object support

YAML to JSON

Convert between YAML and JSON formats

XML Formatter

Format and validate XML

Color Picker

Pick colors with eyedropper and copy values

Box Shadow Generator

Visual CSS box-shadow builder with multiple shadows

Chmod Calculator

Unix file permissions calculator: numeric and symbolic format

GitHub README Generator

Generate beautiful README files for GitHub projects

Regex Pattern Library

Catalog of ready-to-use regex patterns with search and testing

CSS Animation Builder

Visual CSS animation builder with keyframes and live preview

Developer Tools — free online tools

Professional online tools for developers: formatters, validators, decoders, testers and references. JSON, CSS, JavaScript, SQL, HTML, regex, JWT, YAML, XML — all available right in your browser. No extensions needed.

What's included in "Developer Tools"

  • JSON Formatter, minifier and validator

  • Regex tester with match highlighting

  • JWT Decoder and validator

  • CSS/JS/HTML/SQL formatters

  • YAML ↔ JSON converter

  • Code Diff Checker

  • CSS Flexbox and Grid Playground

  • HTTP status codes reference

Who are these tools for

All tools work right in your browser without installation — data is processed locally.

Other tool categories

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