Developer Utilities
No-bloat tools for everyday developer workflows. Fast, offline-capable, and built with a terminal aesthetic.
Cron Expression Generator
Build and parse cron expressions visually. Generate human-readable descriptions and preview next execution times.
JSON Formatter
Format, validate, and minify JSON. Supports nested structures and diff comparison.
Base64 Encoder
Encode and decode Base64 strings. Supports text, URLs, and binary data.
JWT Decoder
Decode and inspect JWT tokens. View header, payload, and signature details.
Regex Tester
Test regular expressions with live matching, group highlighting, and explanations.
Color Converter
Convert colors between HEX, RGB, HSL, and more. Pick colors visually.
Timestamp Converter
Convert Unix timestamps to human-readable dates. Supports ms/s, UTC/local, and relative time.
UUID Generator
Generate RFC 4122 UUID v4 identifiers. Bulk generate up to 20 with individual copy.
URL Encoder
Encode or decode URL strings with encodeURIComponent or encodeURI.
Unicode Converter
Bidirectional text ↔ \uXXXX unicode escape conversion. Supports Java .properties native2ascii format.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously. File hash supported.
SQL Formatter
Format SQL with indentation, uppercase keywords, and line breaks, or minify it.
Diff Checker
Compare two texts and highlight additions and deletions. Line or word mode.
HTML Entity Encoder
Encode HTML special characters into entities or decode them. & → & and more.
Markdown Editor
Live Markdown preview — edit on the left, see rendered output on the right.
Lorem Ipsum Generator
Generate placeholder text by paragraphs, sentences, or words. English and Korean options.
Password Generator
Generate secure random passwords with configurable length and character sets. Strength meter included.
chmod Calculator
Bidirectional Unix file permission calculator. Checkboxes ↔ numeric (755) with presets.
CSV ↔ JSON Converter
Convert between CSV and JSON bidirectionally. Delimiter selection and table preview.
LLM Cost Calculator
Compare API costs for GPT, Claude, Gemini and hundreds of models in real time by entering token counts.
AI Tools Comparison
Compare major AI tools across Chat, Coding, and Image categories. Personally tested tools are marked.
AI Prompt Library
1,000+ AI prompts across Development, Writing, Business and more. Search and copy instantly.
Percentage Calculator
Calculate percentage change, percentages, and discounts in real time. Handy for shopping, investing, and salary negotiations.
Multiplier Calculator
Compare additive vs multiplicative buff efficiency in games. Calculate multi-buff stacks and real DPS increase instantly.
IP Lookup
Find your public IP address and location instantly. See country, region, ISP, and timezone at a glance.
Number Base Converter
Convert between binary, octal, decimal, and hex in real time. Supports negatives and instant copy.
Text Case Converter
Convert text to camelCase, snake_case, kebab-case and 5 more naming conventions instantly.
Word Counter
Count words, characters, sentences, paragraphs, and reading time in real time.
HTTP Status Codes
Browse and search all 1xx–5xx HTTP status codes. Click any code to copy.
Data Size Converter
Convert B, KB, MB, GB, TB, PB in real time. Supports both SI (1000) and binary (1024) modes.