Free, fast, no installation needed - use directly in your browser
Configure name list, big-font rolling lottery with shortcuts and fullscreen
Set countdown timer with quick presets and custom time, persists across page refresh
Simple online notepad with auto-save to localStorage and word count
Online stopwatch with lap recording, keyboard shortcuts and refresh persistence
Simulate coin flipping with 3D animation, custom flip count and statistics
Online JSON formatter, minifier and validator
Online word and character counter for Chinese and English text
Text case converter with camelCase, snake_case and more formats
Online Markdown editor with live preview, supports GFM syntax, tables, code highlighting, and math formulas
Online text comparison with highlighted differences
Convert between actual newlines and literal \n
Convert numbers to Chinese uppercase characters and financial format
Escape and unescape JSON strings for embedding in API parameters
Calculate days between dates or add/subtract days
Installment loan calculator with equal installment or equal principal, repayment schedule export
Reverse-calculate the real APR from principal, monthly payment and term
Mortgage prepayment calculator with partial / full payoff, compare saved interest, shortened term and payment changes
Calculate mortgage monthly payment, interest and total repayment with equal installment or equal principal
Calculate Body Mass Index and assess health status
Convert length, weight, temperature, area, volume and more units
Online UUID v4 generator with batch support
Convert between Unix timestamps and date/time formats
Online random password generator with customizable length and character types
Convert between HEX, RGB, HSL color formats with color picker and live preview
Parse Cron expressions and view next execution times
Generate QR codes for text and URLs with download support
Convert JSON to TypeScript, Go, Python and other language model definitions
Visually build Cron expressions for scheduled tasks
Convert between Python dicts and JSON with auto-detection
Online Base64 encoder and decoder with UTF-8 support
Online URL encoder and decoder
Online hash generator supporting MD5, SHA-1, SHA-256, SHA-512
Convert between text and Unicode escape sequences
Convert between binary, octal, decimal and hexadecimal
Decode JWT tokens to view Header and Payload
Batch image compression for JPG/PNG/WebP, 100% local with zero upload, PNG uses k-means palette quantization (same as TinyPNG)
Online image resize tool with custom width/height, aspect ratio lock, powered by Canvas
Online image crop tool with custom crop area and common aspect ratio presets
Online image watermark tool with text watermark, custom font, color, opacity and position
Upload image to generate Base64 string or Data URL, copy with one click
Input SVG code, set output size, preview in real-time and download as PNG