QBCOO Online Toolbox
Free, privacy-safe online developer tools. All computation runs locally in your browser β your data never leaves your device.
All Tools (24/25 available)
JSON Formatter
Online JSON formatting, validation & minification with syntax highlighting and error location
Dev ToolsBase64 Encoder / Decoder
Online Base64 encode/decode with full Unicode support
EncodingTimestamp Converter
Unix timestamp to date/time conversion with second/millisecond precision
Dev ToolsMD5 / SHA Hash Generator
Generate MD5, SHA1, SHA256 hashes for text and files
SecurityColor Converter
Convert between HEX, RGB, HSL & HSV color formats with live preview
DesignWord Counter
Online word & character counter with CJK/English mixed text support and frequency analysis
TextImage Format Converter
Convert images between WebP, PNG, JPEG, SVG and more formats
ImageImage Compressor
Online lossless/lossy image compression with batch processing and quality adjustment
ImageAI Prompt Optimizer
Intelligently optimize AI prompt structure, auto-supplement context and constraints
AIOnline Stopwatch
Online stopwatch & countdown timer with lap recording and alerts
OfficeRegex Tester
Online regex debugger with match highlighting, group extraction and pattern library
Dev ToolsURL Encoder / Decoder
URL/URI encoding and decoding with support for full URLs and individual parameters
EncodingQR Code Generator
Free online QR code generator with customizable color, size and error correction level
ImageUUID Generator
Batch generate UUID v4 online with case toggle and bulk export
Dev ToolsPassword Generator
Generate secure random passwords with custom character sets and strength evaluation
SecurityCase Converter
Convert between 9 naming styles: camelCase, snake_case, PascalCase, kebab-case and more
TextNumber Base Converter
Real-time conversion between binary, octal, decimal and hex with BigInt support
Dev ToolsText Sort & Dedupe
Sort and deduplicate text lines online with ascending, descending, random and case options
TextHTML Entity Encoder / Decoder
Encode/decode HTML entities in named, decimal and hexadecimal formats
EncodingUnicode Converter
Convert between \uXXXX escape sequences and raw text with code point analysis
EncodingCron Expression Parser
Parse cron expressions into human-readable descriptions and calculate next execution times
Dev ToolsJWT Decoder
Decode JWT tokens online β view Header, Payload and automatically detect expiration
Dev ToolsYAML β JSON Converter
Bidirectional YAML/JSON conversion with syntax validation and custom indentation
Dev ToolsText Diff Checker
Compare text differences online with side-by-side and unified views, highlighted additions and deletions
TextMarkdown Preview
Live Markdown preview editor with GFM support (tables, task lists, code blocks)
TextWhy QBCOO?
Privacy First
All tools run locally in your browser. Your data is never uploaded to any server.
Blazing Fast
Static pages served via CDN. Millisecond load times with zero redundant requests.
Continuously Updated
Developer-driven, new practical tools added regularly to keep up with the latest tech trends.