MicroTools — Free Fast Online Developer & Creator Utilities

High-performance, 100% client-side web utilities and developer guides. Zero server latency, no registration required.

Interactive Developer Utilities

IPv4 Subnet Calculator & CIDR Visualizer: Calculate usable host ranges, broadcast addresses, and binary masks.
JWT Decoder & Inspector: Secure client-side JSON Web Token claim debugger and signature validator.
Network Port Reference Directory: Search common TCP & UDP ports with security vulnerability alerts.
Cron Job Generator & Translator: Build POSIX crontab expressions visually with human English descriptions.
QR Code Generator & Scanner: High-resolution SVG/PNG QR codes with Wi-Fi support and camera decoding.
Hex to ASCII & String Converter: Bidirectional hex converter with custom delimiters.
JSON Formatter & Validator: Fast JSON prettifier and syntax validator.
JSON to CSV Converter: Bidirectional data conversion with Excel dialect support.
Base64 Image Converter: Convert images to Data URIs or decode Base64 back to file.
Strong Password Generator: Cryptographically secure random password and passphrase generator.
QRIS Merchant Fee Calculator: Calculate MDR settlement fees for Indonesian QRIS transactions.
TLV Parser: Decode Tag-Length-Value binary telemetry strings.
MAC Address OUI Lookup: Identify network card hardware manufacturers.
Meta Tag & OpenGraph Analyzer: Preview social media snippets and SEO meta tags.

The Complete Guide to IPv4 Subnetting & CIDR — Learn binary math, subnet masks, and AWS VPC partitioning.
Demystifying JSON Web Tokens (JWT) — Architecture, cryptographic signature verification, and security best practices.
Essential Network Ports: Complete TCP & UDP Reference — Layer 4 transport protocols and firewall hardening.
Mastering Cron Expressions & Scheduling — 5-field syntax, special operators, and Linux/Kubernetes tips.
How QR Codes Work: Reed-Solomon Error Correction — Matrix geometry, encoding modes, and self-healing data.
Base64 Encoding Demystified: 33% Size Overhead & Performance — Data URI trade-offs in modern web apps.