34 tools available

Productivity & Utilities

Browser-native utility tools that execute 100% locally on your computer. No user accounts, registration, or server-side communication.

Pomodoro Timer

This is a productivity tool that alternates between 25 minutes of concentration time and 5 minutes of break time, and notifies you with a sound or desktop notification when the work is completed.

ReactWeb Audio API
Launch Tool

Random Picker

The entered name list will be shuffled, randomly divided into teams, and representatives will be selected using a roulette wheel.

Fisher-Yates ShuffleCSS Animations
Launch Tool

Speech to Text

The audio obtained from the microphone is transcribed in real time and output as text that can be edited and copied.

Web Speech API (SpeechRecognition)
Launch Tool

Flashcard App

Create an original vocabulary book and perform memorization efficiently based on the timing of the forgetting curve (spaced repetition).

ReactIndexedDB
Launch Tool

Metronome

This is a rhythm/performance tool that plays a click sound at a precise tempo according to the specified BPM and time signature, and makes the screen blink.

ReactWeb Audio API
Launch Tool

Breathing Timer

This is a breathing method guidance tool that helps you meditate and relieve stress by following an animation that tells you when to breathe (inhale, hold, exhale).

ReactCSS Transitions
Launch Tool

Typing Test

Test your character input speed (WPM) and accuracy by accurately typing short English or Japanese Romaji texts within a time limit.

ReactTyping Analytics
Launch Tool

Noise Meter

The surrounding volume (sound pressure level) from the microphone is collected in real time, and the simple decibel (dB) value of the entire environment is displayed on a meter.

ReactWeb Audio API
Launch Tool

Screen Tester

Displays the entire screen in a single color (red, green, blue, white, black, etc.) and inspects the LCD monitor for missing dots, color unevenness, and light leakage.

ReactFullscreen API
Launch Tool

Random Generator

Performs dice rolling, coin tossing, and generation of a random number list within a specified range with intuitive 3D-like animation.

ReactRandom Math
Launch Tool

Piano Synth

A piano keyboard that runs on your browser. You can enjoy simple performances by selecting a sound wave waveform and assigning keys on your mouse or PC keyboard.

ReactWeb Audio API
Launch Tool

Math Drill Generator

Randomly generate quizzes on addition, subtraction, multiplication, and division. It is optimized for print layout (A4), and you can also toggle display/hide of answers.

ReactPrint CSS
Launch Tool

Habit Tracker

Enter the daily goals you want to make into a habit (exercise, study, etc.), check the calendar on the day you achieve them, and display a list of your continuation rates.

ReactLocalStorage API
Launch Tool

World Clock

Display the current time in major world cities side by side in analog and digital format, and use the slider to compare time differences (meeting candidate times, etc.).

ReactDate Logic
Launch Tool

BMI Calculator

Based on height, weight, age, and activity intensity, obesity degree (BMI), basal metabolism (BMR), and total calorie expenditure (TDEE) are calculated and drawn on a visual meter.

ReactHealth Formulas
Launch Tool

Pixel Art Editor

You can create pixel art on a 16x16 or 32x32 grid, set layers and animation frames, and save it as a transparent PNG or GIF animation.

ReactCanvas API
Launch Tool

Maze Generator

You can play the game by generating a random maze using an algorithm and manually aiming for the goal, or you can watch the automatic solving process of the search algorithm through animation.

ReactCSS Drawing
Launch Tool

Virtual Art Gallery

While viewing public domain Western masterpieces in high quality, you can customize the frame style and exhibition room lighting, and extract the colors (HEX code) of each work.

ReactCSS 3D Transforms
Launch Tool

Generative Art Math

You can create and save beautiful geometric art in real time by adjusting mathematical models such as fractals, chaotic orbits, and golden angle Fibonacci spirals.

ReactCanvas API
Launch Tool

Noise Generator Healing

This is a concentration BGM synthesis tool that allows you to blend white noise, pink noise, brown noise, and the sounds of rain, wind, and waves to your desired balance.

ReactWeb Audio API
Launch Tool

Stopwatch Lap

This is a tool that can measure lap times and split times infinitely in 1/1000 second units, graph average laps, highest/lowest laps, and export them as CSV files.

ReactrequestAnimationFrame
Launch Tool

Periodic Table Interactive

This is an educational illustrated book that visually displays detailed physical properties, electronic configuration (bohr model animation display), absorption and emission spectra, etc. by clicking on each element in the periodic table of elements.

ReactSVG Animations
Launch Tool

Flight Timezone Planner

When you enter the time difference and flight time, it creates a timeline of how local time progresses during the flight, and graphically calculates your sleep and activity plan to prevent jet lag.

ReactTimezone calculations
Launch Tool

Rubiks Cube 3d

This is a 3D Rubik's Cube that uses CSS 3D Transforms and can be moved intuitively by dragging.

ReactCSS 3D
Launch Tool

Reversi Ai

This is an Othello tool that allows you to play against a mini AI using Monte Carlo tree search and evaluation functions, and analyze the winning rate of each square in a heat map in real time.

ReactMinimax Algorithm
Launch Tool

Sudoku Solver

This is a tool that allows you to play Sudoku puzzles of different difficulty levels, or automatically answers input puzzles using a backtracking algorithm, and visualizes the search process with animation.

ReactBacktracking
Launch Tool

Sound Recorder Sampler

This is a portable sampler that allows you to record environmental sounds and voices from a microphone, and then assign them to a keyboard or drum pad to enjoy sampled performances.

ReactWeb Audio API
Launch Tool

Kanban Board

A secure Kanban board task management tool that saves in LocalStorage, allowing you to move cards intuitively using drag and drop.

ReactHTML5 Drag and Drop
Launch Tool

Ear Age Test

This is a tool that uses the Web Audio API to generate high-frequency sounds from 8kHz to 20kHz to easily measure and test ear age based on the hearing limit.

ReactWeb Audio API
Launch Tool

Simon Says Game

This is a classic brain training game (Simon) in which you memorize the pattern order of panels with lights and sounds, and correctly reproduce sequences that gradually become longer.

ReactWeb Audio API
Launch Tool

Conway Game Of Life

This is a tool that allows you to simulate Conway's Game of Life on your browser and observe the dynamic changes of cell birth and death.

ReactCanvas API
Launch Tool

Slide Puzzle 15

This is a tool that allows you to play the classic 15 puzzles, or create a split puzzle from your own images, and enjoy the automatic shortest strategy animation using the A* algorithm.

ReactA* Search Algorithm
Launch Tool

Mindmap Creator

It is a mind map editor that allows you to easily add nodes with key operations, organize the layout intuitively, and export it as SVG or PNG.

ReactSVG Vectors
Launch Tool

Digital Bookshelf

This is a completely local digital bookshelf where you can take pictures of the covers of the manga and novels you have purchased, register them, and manage your collection by arranging them in order of volume number.

ReactIndexedDB
Launch Tool

Secure Client-Side Sandbox

All tools displayed in this category run locally in your browser sandbox. None of the inputs, file data, or processing logs are sent to any remote servers or APIs.

Category Architecture & Guide

Productivity & Utilities: Comprehensive Guide

Pomodoro timers, habit tracking, unit converters, and offline PWA tools

From focus-boosting Pomodoro timers and personal habit trackers to unit converters, QR code generators, and mind maps, ZeroTools provides a distraction-free suite of daily productivity tools. Every utility supports offline PWA installation, ensuring seamless workflow continuity anywhere.

Offline-First PWA Architecture

Install directly to your home screen or desktop and use all tools without an active internet connection.

Private Data Persistence

Your daily notes and habit tracking metrics remain strictly on your physical device.

Fast, Lightweight & Responsive

Zero background bloat ensures instant tool startup and smooth performance on mobile and desktop.

1IndexedDB Local Storage for Private Habit & Task Management

Track habits, manage Kanban boards, and organize reading lists with data persisted securely in your browser's IndexedDB. Your productivity logs remain on your device with no mandatory account creation.

2Distraction-Free Focus & Daily Utility Workflow

Leverage scientific 25-minute Pomodoro cycles, breathing timers, white noise generators, and quick calculation tools with clean, ad-free, and popup-free interfaces.

Frequently Asked Questions

Q.Will my stored data disappear when I close the browser?
No. Data is saved in your browser's persistent local storage and is restored whenever you revisit the page on the same device.
Q.Can I install ZeroTools as an app on my phone?
Yes! ZeroTools is a Progressive Web App (PWA). Simply select 'Add to Home Screen' in your mobile browser.