Utility
6 tools
Local-first utilities — all processing happens in your browser, no upload.
- ✨ New
Color Converter · HEX RGB HSL Three-way Conversion
Online color format converter for HEX / RGB / HSL. Type any format, the other two sync instantly with live swatch preview. Runs entirely in your browser — nothing uploaded.
Open - ✨ New
JSON Formatter · Prettify · Minify · Validate
Online JSON formatter / minifier / validator with custom indent, lag-free large inputs, and structured error messages. Runs entirely in your browser — JSON never uploaded, safe for sensitive data.
Open - ✨ New
LLM API Inference Cost Calculator – GPT, Claude, Gemini, DeepSeek
Estimate API costs for GPT, Claude, Gemini, DeepSeek and Qwen LLMs with input/output token pricing, prompt caching discounts and USD-CNY conversion. Forecast daily, monthly and yearly bills to plan your AI product budget with confidence.
Open - ✨ New
2026 May Day Overtime Pay Calculator – Daily Rate Checker
Locked to China's 2026 May Day holiday (May 1–5). Check each day you worked overtime to instantly see per-day and total pay at the correct multiplier: 3× for statutory holidays (May 1–2) and 2× for compensatory rest days (May 3–5). Salary folded locally in your browser — no data uploaded.
Open - ✨ New
Provident Fund Withdrawal Calculator: 7 Cities, 6 Scenarios
Check housing provident fund withdrawal limits for Beijing, Shanghai, Guangzhou, Shenzhen and 3 more cities. Covers 6 withdrawal scenarios — home purchase, loan repayment, rental, resignation, serious illness and retirement — with required materials and frequency rules.
Open - ✨ New
QR Code Generator - Online Free Local Browser Tool
Free online QR code generator for text, URLs, WiFi and vCard. Customize error correction level, size and colors, then download as PNG. All processing happens locally in your browser, no upload.
Open