The dev
toolbox
that slaps.
Format, encode, generate, convert. Everything runs in your browser — your data never leaves the tab.
Encoders & Decoders
4Base64 Encode/Decode
Encode text to Base64 or decode Base64 back to text
URL Encode/Decode
Encode or decode URL components and query strings
JWT Decoder
Decode and inspect JSON Web Tokens without verification
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text
Formatters & Validators
4JSON Formatter
Format, validate, and minify JSON data with syntax highlighting
Code Formatter
Format JavaScript, TypeScript, HTML, CSS, and SQL code with Prettier
Diff Checker
Compare two texts and see the differences highlighted
Regex Tester
Test regular expressions with real-time matching and explanation
Generators
4UUID Generator
Generate UUID v4 and ULID identifiers
Password Generator
Generate strong, random passwords with custom rules
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words
QR Code Generator
Generate QR codes from text, URLs, or any data
Converters
4Timestamp Converter
Convert between Unix timestamps, ISO dates, and human-readable formats
Color Converter
Convert colors between HEX, RGB, HSL, and CMYK formats
Cron Expression Parser
Parse cron expressions into human-readable schedules
Markdown Editor
Write Markdown with live preview and syntax highlighting
CSS Tools
3SEO & Config
4Meta Tag Generator
Generate HTML meta tags and Open Graph tags for SEO
robots.txt Generator
Create robots.txt files for search engine crawling rules
.gitignore Builder
Build .gitignore files from popular templates for any stack
Chmod Calculator
Calculate Unix file permissions in numeric and symbolic notation
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Private by default
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No accounts
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