UD5 Toolkit
LED Series Resistor Calculator - Online Current Limiting Tool
Calculate the correct series resistor for an LED based on supply voltage, LED forward voltage, and desired current. Circuit diagram shown. Local only.
Advanced Online Scientific Calculator - History & Memory
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Ohm's Law Calculator - Online Voltage Current Resistance Power
Enter any two values (voltage, current, resistance, power) and compute the others. Visual triangle helper and formula display. Instant local calculation.
Number Memory Trainer - Online Recall Digits
A sequence of digits flashes for a few seconds. Type it back. Increase length. Improve your working memory.
Meeting Cost Calculator - Online Time & Money Waster
Calculate the real monetary cost of a meeting by attendees' hourly rates. A humorous yet insightful productivity tool. All local calculation.
Wine Must Adjuster – Online Sugar, Acid & Tannin Calculator
Enter your must volume and current Brix, TA, and pH to calculate additions of sugar, acid blend, or tannin. Standard winemaking formulas.
Currency Exchange Fee Calculator - Online Hidden Cost Revealer
Compare the real cost of currency exchange including hidden mark-ups and service fees. See how much you lose per transaction. Local educational tool.
Intl API Explorer - Online Format Numbers, Dates, Lists
Explore all Intl APIs: NumberFormat, DateTimeFormat, RelativeTimeFormat, ListFormat. See outputs for any locale. Powerful i18n.
Units of Measurement Reference - Online Quick Guide
Search and browse a comprehensive table of SI units and common imperial conversions. For students and engineers.
Water Intake Tracker - Online Daily Hydration Logger
Log your daily water consumption with one click. Set a goal and track progress. Data stored locally for privacy. Simple and clean interface.
HTTP Headers Reference - Online Search & Descriptions
Browse a searchable list of standard HTTP request and response headers with explanations. Quick dev help.
Fish Quarantine Countdown – Online New Arrival Observation
Set a date when a new fish arrives and get a daily checklist for observation. Countdown to safe introduction.
Voice Memo Recorder - Online Record & Download Audio
Record audio directly from your microphone and download it as a WAV file. Perfect for quick notes. No upload, fully offline support.
Smoke Detector Battery Reminder – Online 6‑Month Alarm
Set a reminder to change smoke detector batteries every 6 months. Optional sound alert and visual countdown. Local browser notification, stay safe.
HTTP Security Header Checker - Online HSTS, CSP, X-Frame Analysis
Paste response headers string and get a security audit. Check presence and configuration of key security headers. Local analysis.
HTML Sanitizer - Online Clean Dangerous Tags & XSS Prevention
Strip dangerous HTML tags and attributes (scripts, onclick) to prevent XSS attacks. Safe iframe preview. Local sanitation engine.
Crossword Solver - Online Find Words by Pattern ?a?e
Enter word pattern with ? for unknown letters and known letters to find matching dictionary words. Essential crossword help. Local dictionary.
Simple Tax Credit Checker - Online Estimate GST/HST & Climate
Quick eligibility estimator for Canadian GST/HST credit and climate action incentive based on income and family size. For informational purpose only.
World Clock - Online Current Time Across Cities
Display current time for multiple cities worldwide. Add and remove locations. See day/night indicator. Lightweight and always accurate.
HTTP Status Codes Reference - Online Quick Cheat Sheet
A complete reference of HTTP status codes with explanations. Search and filter by code or category. Useful for API developers and web debugging. Static and fast.
Global Meeting Time Finder - Online Multi‑Zone Overlap Tool
Select cities and see a 24-hour grid highlighting compatible meeting times. Drag to find a slot that works for everyone. Daylight saving aware.
Earthquake Safety Drill Timer – Online Practice Alert
Simulate an earthquake alarm with a countdown and visual instructions for Drop, Cover, and Hold On.
Time Zone Converter - Online World Clock & Meeting Planner
Compare time across multiple time zones and find a suitable meeting time. Convert a specific time to various cities. Browser-based and always accurate.
Eye Strain Relief Timer - Online 20-20-20 Rule Reminder
Timer that reminds you to look at something 20 feet away for 20 seconds every 20 minutes. Customizable intervals and subtle sound/visual alerts.
HTTP Status Code Reference - Online Search & Meanings
Look up any HTTP status code and see its meaning, RFC reference, and example. Full offline reference.
Touch Gesture Recognizer - Online Detect Swipe, Pinch, Rotate
Perform gestures on a canvas and see them detected in real time. Logs swipe direction, pinch scale, and rotate angle.
Treasure Hunt Clue Maker – Online Create Rhyming Clues
Enter hiding places and get a set of rhyming clues to print. Fun for kids' parties.
Phishing Email Checker - Online Suspicious Link Analyzer
Paste email headers or body text to quickly spot phishing signs, suspicious domains, and obfuscated links. Educational and private.
Posture Reminder - Online Sit Straight Alert & Timer
Set recurring audio/visual reminders to check and correct sitting posture. Adjustable interval and notification style. Helps reduce back pain from desk work.
Movie Watchlist - Online Save Films to Watch
Keep a simple list of movies you want to watch. Add notes and check them off. Purely local storage.
Cast & Bandage Shower Timer – Online Waterproof Cover Check
Timer to remind you to limit shower water exposure even with a cast cover. Keep your cast dry.