Developer Tools
Free Developer Toolkit
Essential tools for developers — JSON formatter, Base64, Regex tester, Color picker, UUID generator, Hash generator, HTML encoder and more. All run in your browser, private & instant.
12
Tools
100%
Private
0
Server Calls
{ } JSON
🔐 Base64
🔍 Regex
🎨 Color
🔑 UUID
🔒 Hash
🌐 HTML Encode
🔗 URL Encode
🪙 JWT Decoder
📄 Text Diff
🗜️ CSS Minifier
📝 Markdown
Advertisement
JSON Formatter & Validator
Beautify, minify, validate and analyse your JSON data
Input JSON Paste your JSON here
Output
Output will appear here...
Base64 Encoder / Decoder
Encode or decode any text or data to/from Base64 format
Input
Output
Output appears here...
Regex Tester
Test regular expressions with live match highlighting and group capture
Regular Expression
Test String
Highlighted Matches
Color Picker & Converter
Pick colors and convert between HEX, RGB, HSL, CMYK and CSS variables
CSS Output
Shades & Tints
Contrast Info
UUID / GUID Generator
Generate v4 UUIDs, NanoIDs and custom unique identifiers
Generated IDs
Click Generate...
Advertisement
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 hashes from any text
Input Text
Hash Values
Hash values will appear here...
HTML Encoder / Decoder
Encode special characters to HTML entities and decode them back
Input
Output
Output appears here...
URL Encoder / Decoder
Encode or decode URLs and query string parameters
Input
Output
Output appears here...
JWT Token Decoder
Decode and inspect JWT tokens (Header, Payload, Signature) — no secret needed
JWT Token
Decoded Payload
Decoded JWT parts appear here...
Text Diff Checker
Compare two text blocks and highlight additions, deletions and changes
Text A (Original)
Text B (Modified)
CSS Minifier & Beautifier
Minify CSS to reduce file size or beautify compressed CSS for readability
Input CSS
Output
Output appears here...
Markdown Preview
Write Markdown and see a live preview rendered as HTML
Markdown Input
Live Preview
Advertisement
⚠️
Educational use only. All tools and course content on SmartUtilz are for informational and study purposes. Results must be independently verified by a qualified engineer before use in any design or safety-critical application. Read full disclaimer →