UD5 Toolkit
Polygon Centroid Calculator - Online Center of Mass
Find the centroid (center of mass) of any convex polygon by entering vertex coordinates. Useful for physics and design.
Speed Distance Time Calculator - Online SDT Formula Tool
Speed Distance Time Calculator
Enter any two values and instantly get the third. Supports multiple units with automatic conversion.
Speed
Distance
Time
Formula & Steps
Enter two valid numbers to see the calculation steps.
Frequently Asked Questions
Speed = Distance Ă· Time. Just divide the distance traveled by the time taken, and you get the average speed.
Distance = Speed Ă— Time. Multiply the speed by the travel time to find the distance covered.
Time = Distance Ă· Speed. Divide the distance by the speed to obtain the time required.
Absolutely. This tool automatically converts any combination of units. For example, you can enter distance in miles and time in minutes, then get the speed in km/h.
Speed: m/s, km/h, mph, knot, ft/s, km/s, cm/s. Distance: meter, kilometer, mile, foot, yard, nautical mile, centimeter, millimeter, inch. Time: second, minute, hour, day.
For precision, the calculator keeps up to six significant digits after conversion. You can round the number as needed; the extra digits simply reflect exact conversion factors.
Online Metronome - Precise Beats per Minute & Time Signature
A precise online metronome with adjustable BPM, beat emphasis, and time signature. Works offline. Essential for musicians.
Day Counter & Duration Tracker - Online Since/Until
Enter two dates and see the exact number of days, weeks, and workdays between them. Also shows the countdown or days since.
Online Metronome with Subdivisions - Precise Rhythm Trainer
Play a metronome with adjustable BPM, time signature, and subdivisions (eighth, triplet, sixteenth). Tap tempo and visual flash. Works offline for practice.
Class Attendance Tracker - Online Log Present / Absent Percentage
Track attendance for multiple subjects. Mark present/absent and see percentage. Data in localStorage. Simple student tool.
Flow Rate Converter - Online GPM L/s & mÂł/h Tool
Convert volumetric flow rate units: gallons per minute, liters per second, cubic meters per hour. Useful for plumbing and hydraulics.
Coin Toss Probability Demonstrator – Online Long‑Run Simulator
Virtual flip coins thousands of times and see the heads/tails ratio converge to 50%. Interactive law of large numbers.
PX to VW/VH Converter - Online Responsive Unit Calculator
Convert pixel values to viewport‑relative units (vw, vh, vmin, vmax) based on a selected breakpoint. Precise responsive design.
Event Countdown Timer - Online Days Until Birthday Wedding Vacation
Set any future date and see a live countdown in days, hours, minutes, seconds. Fun animated display. Save multiple countdowns locally.
Text Alignment Tool - Online Left/Center/Right/Justify
Paste text and align it left, center, right, or fully justify by inserting spaces. Simple formatting helper. Pure browser.
PX to VW/VH/VMAX/VMIN Converter - Online Responsive Calculator
Convert pixel values to viewport‑relative units (vw, vh, vmax, vmin) for a specified breakpoint. Includes DVH and SVH. Essential for fluid layouts.
Robots.txt Validator & Parser - Online Check Syntax
Paste robots.txt content and parse it to check validity, find disallowed paths. Educational SEO tool. Local processing.
Robots.txt Validator - Online Check Syntax & Rules
Paste a robots.txt file and validate its syntax. See if a specific user‑agent can access a path. Essential for webmasters.
Baby Feeding Log - Online Track Breast & Bottle Patterns
Record feeding times, side (left/right for nursing) or oz for bottle. Track daily patterns. Data stays in your browser. Simple newborn helper.
WebGPU Compute Benchmark - Online GPU Performance Test
Measure your browser's GPU compute power using a simple WebGPU matrix multiplication. See raw FLOPS and compare with peers. Fully client‑side.
PX to EM/REM Converter - Online Responsive Unit Calculator
Convert pixel values to em and rem units based on a base font size. Bidirectional. Must‑have for front‑end developers.
On‑Screen Pixel Ruler - Online Measure Elements in Browser
Drag a virtual ruler across your screen to measure pixel distances. Horizontal and vertical guides. Useful for UI designers checking alignment.
REM to PX Converter - Online Root EM Unit Calculator
Convert REM values to pixels and vice versa based on your root font size. Essential for scalable web typography.
Speech Timer – Online Practice Presentations with WPM
Paste your speech, set time limit, and practice with a pacing indicator (words per minute). Refine delivery.
DOM Size Inspector - Online Count & Warn for Performance
Count total DOM nodes on the current page and show warnings if limits exceed best practices. Keep the DOM lean.
:focus‑visible Tester - Online Keyboard‑Only Focus Ring
Compare :focus and :focus‑visible styling. See which one applies when using mouse vs. keyboard. Accessible focus management.
Plant Watering Reminder - Online Houseplant Care Scheduler
Set watering schedules for multiple plants with visual alerts. Shows which plants need water today based on last watered date. Data stored locally.
Robots.txt Generator - Online Create & Validate Robots File
Build a properly formatted robots.txt file with user-agent rules and sitemap location. Validate syntax in real time. Essential for webmasters.
Browser Screen Recorder - Online Record Tab & Download WebM
Record your screen, window, or tab with audio directly in the browser. Download the recording as a WebM file. No upload.
Browser Screen Recorder - Online Record Tab & Download WebM
Record your screen, window, or tab with audio directly in the browser. Download as WebM. No extension required.
Meeting Speaker Timer - Online Countdown Per Agenda Item
Set a list of agenda items with allocated minutes. Advance through speakers and see remaining time visually. Keep meetings on track.
Regex Catastrophic Backtracking Tester - Online Benchmark
Test a regex against long strings and measure execution time. Detect catastrophic backtracking patterns. Visual warning if slow.
Potty Training Log – Online Record Accidents & Successes
Simple tracker to record potty attempts, successes, accidents. See patterns. Data stays local. Aids in toilet training journey.
Simple Water Tracker - Online Click Glass Count
Tap a glass icon each time you drink a cup of water. See your daily intake. Reminders optional. Local storage.
Web USB Console - Online Claim & Talk to USB Device
Request a USB device and communicate with it using the Web USB API. See vendor and product IDs. Experimental.