Free Developer Tools
JWT decoder, JSON & YAML formatters, regex tester, encoders, and 25+ more — instantly in your browser. No signup. No servers. No data stored.
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Popular tools
JWT Decoder & Debugger
Decode and inspect JWT header, payload, and signature instantly. Free jwt.io alternative — 100% private, runs in your browser.
JSON Formatter & Validator
Format, validate, and beautify JSON instantly in your browser. 100% private — your data never leaves your device.
YAML ↔ JSON Converter
Convert YAML to JSON and JSON to YAML instantly. Free, private, and runs 100% in your browser.
Color Converter
Convert colors between HEX, RGB, and HSL with WCAG contrast ratios. Free, instant, runs in your browser.
cURL to Code Converter
Convert cURL commands to JavaScript fetch or Python requests code. Free, private, runs in your browser.
Text Diff Checker
Compare two text blocks and highlight line-by-line differences. Free diff tool, runs in your browser.
JSON Tools
7JSON Formatter & Validator
Format, validate, and beautify JSON instantly in your browser. 100% private — your data never leaves your device.
Open tool →JSON Minifier
Minify and compress JSON by removing whitespace. Fast, free, and runs 100% in your browser.
Open tool →JSON to CSV Converter
Convert JSON arrays to CSV format instantly. Handles nested objects and custom delimiters. 100% client-side.
Open tool →JSON Diff
Compare two JSON documents side by side and highlight differences. Free, private, runs in your browser.
Open tool →JSON Path Tester
Test JSONPath queries against JSON data. Find and extract values with JSONPath syntax. 100% private.
Open tool →YAML ↔ JSON Converter
Convert YAML to JSON and JSON to YAML instantly. Free, private, and runs 100% in your browser.
Open tool →JSON Schema Validator
Validate JSON documents against a JSON Schema instantly in your browser. Supports formats, types, and required fields.
Open tool →Code Formatters
5HTML Formatter
Format and beautify HTML with proper indentation. Free HTML prettifier, runs in your browser.
Open tool →CSS Formatter & Minifier
Format or minify CSS stylesheets. Free CSS beautifier and compressor. 100% client-side.
Open tool →JavaScript Formatter
Format and beautify JavaScript code with Prettier. Free JS prettifier, private and fast.
Open tool →XML Formatter
Format and beautify XML with proper indentation. Free XML prettifier, 100% client-side.
Open tool →SQL Formatter
Format and beautify SQL queries with keyword casing and indentation. Supports standard SQL, PostgreSQL, and MySQL.
Open tool →Generators
3UUID Generator
Generate cryptographically random UUID v4 and time-ordered UUID v7 identifiers. Free and instant.
Open tool →Password Generator
Generate secure random passwords with customizable length and character sets. Uses crypto.getRandomValues.
Open tool →QR Code Generator
Create QR codes for URLs, text, WiFi, and more. Download as PNG. 100% client-side generation.
Open tool →Encoders & Decoders
5Base64 Encode/Decode
Encode text to Base64 or decode Base64 to text. Supports UTF-8. 100% client-side, no data stored.
Open tool →URL Encode/Decode
URL-encode or decode strings with encodeURIComponent. Free, fast, and private.
Open tool →Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text. Uses Web Crypto API. Private and fast.
Open tool →Unicode Escape Converter
Encode text to JavaScript \u escapes or U+ notation and decode escaped Unicode back to characters.
Open tool →PEM Decoder
Inspect PEM certificates and public keys. Shows DER size, SHA-256 fingerprint, and hex preview.
Open tool →Text Tools
4Text Diff Checker
Compare two text blocks and highlight line-by-line differences. Free diff tool, runs in your browser.
Open tool →Markdown Preview
Write Markdown and see a live HTML preview. Free markdown editor, everything stays in your browser.
Open tool →Word & Character Counter
Count words, characters, sentences, paragraphs, and reading time. Free text analyzer.
Open tool →Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case, slug, and more. Free and instant.
Open tool →Developer Tools
7Regex Tester
Test regular expressions with live match highlighting. Supports flags and capture groups. Runs in your browser.
Open tool →Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds.
Open tool →Cron Expression Explainer
Parse and explain cron expressions in plain English. See next run times. Free cron decoder.
Open tool →JWT Decoder & Debugger
Decode and inspect JWT header, payload, and signature instantly. Free jwt.io alternative — 100% private, runs in your browser.
Open tool →Color Converter
Convert colors between HEX, RGB, and HSL with WCAG contrast ratios. Free, instant, runs in your browser.
Open tool →Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly. Free developer calculator.
Open tool →cURL to Code Converter
Convert cURL commands to JavaScript fetch or Python requests code. Free, private, runs in your browser.
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