DevTools Pro - Developer Toolbox

DevTools Pro: JSON formatter, Base64/URL encoder, timestamp converter, JWT decoder, regex tester. Free & offline.

DevTools Pro is a free, offline developer toolbox that puts 6 essential tools at your fingertips — all running locally in your browser with zero data collection. ━━━━━━━━━━━━━━━━━━━━ 🧰 TOOLS INCLUDED 1. JSON Formatter • Parse & format with tree view (collapsible nodes) • Deep search — find any key or value instantly • Copy entire subtrees as JSON with one click • Minify to single-line output • Handles large files gracefully (progressive rendering) 2. JWT Encode / Decode • Decode: Split header/payload/signature with expiry check • Encode: HS256/384/512 signing via Web Crypto API • 4 payload templates (Basic, Auth, Admin, API) • Custom expiration: minutes, hours, days, or specific date 3. Timestamp Converter • Unix seconds ↔ milliseconds auto-detection • UTC + local time dual display with timezone info • Real-time UTC + local clock (fully offline) • One-click "Now" button 4. Regex Tester • 7 built-in presets (email, URL, phone, IP, Chinese, etc.) • 12 regex snippet buttons for quick insertion • Real-time match highlighting with count • Flag selector (g, i, m combinations) 5. Base64 Encode / Decode • UTF-8 safe — handles Chinese and emoji • Bidirectional encode ↔ decode 6. URL Encode / Decode • Standard encodeURIComponent / decodeURIComponent • One-click copy ━━━━━━━━━━━━━━━━━━━━ 🔒 PRIVACY FIRST • 100% local processing — no data leaves your browser • No analytics, no tracking, no ads • Zero network requests — fully offline • Open privacy policy linked below 🌐 INTERNATIONAL • Full English & Simplified Chinese support • Auto-detects browser language 💡 PERFECT FOR • Frontend/backend developers debugging APIs • QA engineers inspecting JWT tokens • DevOps engineers converting timestamps • Anyone working with encoded data ──────────────────────────── 📬 Support: 13531021638@163.com