istb16

Audio Quality Checker

Score audio quality from WAV/MP3 files or microphone recordings across 5 axes — noise, distortion, reverb, echo, and clarity. Results visualized with a VU meter and radar chart.

Real-time Prefectural Risk Map

Aggregates real-time weather, earthquake, air quality, and heat wave data to rank all 47 prefectures by risk score. Auto-refreshes every 5 minutes — see at a glance where in Japan is most dangerous right now.

SQL Formatter by DB Dialect

Format SQL to match your target database dialect — MySQL, PostgreSQL, SQLite, and more. A handy companion for improving readability of ORM-generated queries or reviewing raw SQL.

Regular Expression Checker

Real-time regular expression testing in your browser with ES2025 support. Catch unintended matches before they reach production validation or string parsing logic.

Client Information Viewer

Check your global IP address in one click. Useful for verifying VPN connections or registering your IP on server allowlists.

VTT Subtitle Formatter

Format timestamps and line breaks in VTT subtitle files for improved readability. Great for video content editing or pre-processing meeting transcription workflows.

KOOS Personal Viewer

Displays your work hours from Koos records at a glance. Get the answer to "how many hours did I work today?" without any extra steps.

Character Zoom Viewer

Enlarge any character to fill the screen. Perfect for those "wait, is that the right character?" moments during code review or document writing.

LINE Creators Collection

A collection of LINE stickers and emoji designed to feel safe and easy to use. Starting with a fluffy bandana sheep, with more to come.

Browser Data Switcher

Switch cookies and localStorage between multiple accounts with one click during development. Save snapshots and restore any state without repeated logout/login cycles. Open source for full transparency.