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All Tools (133)

Personal Finance & Business Suite - A comprehensive personal finance and business suite covering compound interest, emergency funds, net worth tracking, and more.
Wellness & Bio-Tracking Dashboard - A unified dashboard for your health and bio-tracking tools including sleep debt, blood pressure, and breathing coherence.
The Wikipedia Racer - Race to click through Wikipedia hyperlinks to connect two random topics in the fewest clicks.
Typewriter Orchestra - Turn your keyboard into a musical instrument. Every letter key triggers a specific loop or sample.
User Interface Hell - A puzzle game where you must unsubscribe from a fake newsletter, but the UI fights you.
Where on Earth? - Guess your location based on a random satellite view without labels.
The CMYK Master - Mix Cyan, Magenta, Yellow, and Key/Black sliders to match the target color perfectly.
Your Life in Numbers - Input your birth date to see how many times your heart has beaten and historical events you've lived through.
Scream to Jump - Whisper to walk, scream to jump. A game controlled entirely by your voice volume.
Don't Spill The Coffee - Walk around your real house without tilting your phone, or the virtual coffee spills.
The Ring Size Matcher - Place a ring on your screen and adjust the slider to find your exact size (US/UK/EU).
Glasses PD Scanner - Measure the distance between your pupils (PD) using your webcam and a standard card.
The Screen Ruler - Calibrate your screen with a credit card to measure real-world objects using a floating ruler.
Watch & Bracelet Sizer - Visualize how a 40mm vs 44mm watch face would look on your specific wrist size.
Ninja Cam Freeze - Red Light, Green Light played with your webcam. Move to collect coins, freeze when red.
LLM Prompt Engineering Builder - Create precise, hallucination-free prompts for ChatGPT and Claude using proven frameworks like Chain-of-Thought to improve AI responses.
Text Token Usage Calculator - Optimize text to save API costs and fit within LLM context windows by compressing documents into essential tokens.
Free PDF Signer & Editor - Sign documents and fill forms directly in your browser without uploading sensitive contracts to a server.
Bulk Certificate & PDF Editor - Generate certificates in bulk from a list of names or edit PDFs/images. Add text layers with custom fonts, draw and overlay signatures, and export locally.
ADHD Focus Dashboard - A distraction-free interface combining lo-fi music, a task timer, and a to-do list designed to trigger deep work.
Online Eye Chart - Use a screen-accurate 20/20 eye chart for visual referencing and monitoring.
Audio Frequency Response Test - Test your ability to hear audio tones across frequencies from 20Hz to 20kHz.
Tone Frequency Matcher - Find specific audio frequencies using a tone generator to aid in sound therapy.
Visual Contrast Chart - Check for visual refractive errors using a high-contrast fan chart.
Blue Light Detector - Analyze your environment's lighting color temperature to prevent melatonin suppression and improve sleep.
Audio Frequency Age Test - Determine the highest frequency you can hear compared to average age groups.
Online LaTeX Equation Editor - Build complex mathematical formulas visually and export them as clean LaTeX code or high-quality images.
Focus Reading Assistant - Read faster and retain more by converting text into a format that guides eye fixation points.
Text to Speech Preview - Test content accessibility and flow by listening to your text read aloud by various system voices.
Options Strategy Builder - Visually build and analyze complex options strategies like Iron Condors and Straddles with profit/loss diagrams.
Options Theta Decay Visualizer - Visualize how time decay (Theta) affects option prices across different expiry dates.
File Protection Utility - Securely encrypt and decrypt files directly in your browser using standard AES-256 encryption.
Token Format Viewer - Decode and verify JSON Web Tokens (JWT) locally to inspect claims without sending data to a server.
Photo Metadata Cleaner - Protect your privacy by stripping GPS location and device metadata from photos before sharing online.
Browser Configuration Analyzer - See how trackers identify you online by analyzing your unique browser fingerprint and device hash.
Map Data Visualizer - Visualize your movement history on a private map by parsing your Google Takeout JSON files.
Communication History Graph - Visualize communication patterns and relationship history from exported chat logs over time.
Productivity Time Analyzer - Analyze your browsing habits from history files to find peak productivity hours.
Monitor Refresh Rate Test - Accurately test your screen's refresh rate (Hz) and check for motion blur or ghosting artifacts.
Stuck Pixel Fixer - Attempt to revive stuck pixels on your screen by flashing high-frequency color patterns.
OLED Screen Uniformity Test - Check your OLED display for permanent image retention or burn-in using grey-scale uniformity patterns.
Monitor Calibration Tool - Calibrate your monitor's gamma, contrast, and black levels for accurate color representation.
Dead Pixel Checker - Easily spot dead or stuck pixels on your monitor by cycling through solid RGB color backgrounds.
OLED Burn-In Remover - Run a pixel-refreshing loop of colors to help reduce temporary image persistence on OLED screens.
Backlight Bleed Test - Inspect your monitor for backlight bleeding and IPS glow using a pure black screen test.
Online Stroboscope - Use a flashing screen light at precise frequencies to measure the RPM of rotating objects.
Audio Latency Test - Measure the round-trip delay of your audio setup to check for lag in Bluetooth headphones.
Microphone Frequency Analyzer - Visualize sound frequencies in real-time using a professional FFT spectrum analyzer for your microphone.
Left/Right Stereo Speaker Test - Verify your speaker or headphone channels are correctly oriented with a simple stereo audio test.
Speaker Phase & Polarity Test - Check if your speakers are wired out-of-phase, which can cause hollow sound and lack of bass.
Noise Level Meter (Decibels) - Monitor ambient noise levels and calculate safe exposure limits to protect your hearing.
Microphone Input Lag Test - Test the input lag of your microphone by measuring the delay between sound and system registration.
Phone Vibration Test - Test your device's haptic feedback engine with various vibration patterns and intensities.
Keyboard Latency Test - Accurately measure the input lag of your keyboard in milliseconds to test performance.
Mouse Polling Rate Tester - Check your mouse's polling rate (Hz) to ensure it's performing optimally for gaming.
Gamepad & Stick Drift Tester - Test game controllers for analog stick drift and dead zones with a precision visualizer.
Keyboard Ghosting Test - Test your keyboard's N-Key Rollover (NKRO) capabilities to see how many simultaneous keys it registers.
Gyroscope & Accelerometer Test - Log and visualize real-time data from your device's motion sensors to check for faults.
Battery Drain Test - Monitor real-time battery discharge rates to identify excessive power drain or faulty cells.
Printer Test Page Generator - Generate diagnostic color bars and alignment grids to test and clean your printer heads.
Internet Stability Test - Analyze your connection quality by measuring ping jitter and packet loss consistency over time.
Wi-Fi Dead Zone Logger - Map your home's Wi-Fi dead zones visually using augmented reality signal strength tracking.
Find Lost Bluetooth Device - Locate lost headphones or gadgets by tracking their Bluetooth signal strength (RSSI) proximity.
Crontab Generator & Visualizer - Create and verify Cron schedules with a human-readable description of when tasks will run.
Regex Visualizer & Debugger - Understand complex Regular Expressions by converting them into interactive visual flowcharts.
Online SQLite Viewer - Open and explore SQLite database files instantly in your browser without uploading them.
Docker Compose Validator - Validate and lint your Docker Compose YAML files to catch syntax errors and configuration issues.
Web Serial Terminal - Communicate with hardware devices like Arduinos via Serial ports directly from your browser.
Online LUT Previewer - Apply cinematic 3D LUTs (.CUBE files) to your images in real-time to preview color grades.
Color Blindness Simulator - Test your designs for accessibility by simulating different types of color blindness.
On-Screen Ruler - Measure pixel dimensions and alignment on any webpage with a floating transparent ruler.
Invisible Image Watermarker - Embed invisible copyright data into your images that survives compression but remains undetectable to the human eye.
Audio Video Sync Test - Use a visual flash and beep tool to precisely calibrate and fix audio-video synchronization issues.
Sensor Dust Checker - Find dust spots on your camera sensor easily with a high-contrast visualization tool.
Camera Field of View Simulator - Simulate and compare the field of view for different focal lengths and sensor sizes.
Online Gerber Viewer - Inspect PCB manufacturing files (Gerber) layer-by-layer in your browser.
Bluetooth LE Scanner - Scan for nearby Bluetooth Low Energy (BLE) devices and inspect their services and characteristics.
Resistor Color Code Scanner - Identify resistor values instantly by scanning their color bands with your camera.
Logic Gate Simulator - Build and test digital circuits with interactive logic gates to understand boolean operations.
Box Breathing Guide - Reduce anxiety and calm your nervous system with a guided haptic Box Breathing tool.
CPR Metronome (110 BPM) - Maintain the correct rhythm for chest compressions during CPR with a 110 BPM audio-visual guide.
Metal Detector & Stud Finder - Use your phone's magnetometer to detect metal studs and wires inside walls.
Video Flashing Test (Epilepsy) - Analyze video content for dangerous flashing patterns that could trigger photosensitive seizures.
Probability Distribution Calculator - Plot and analyze Normal, Binomial, and Poisson probability distributions.
Data Anonymization Tool - Automatically scrub sensitive PII like names and emails from datasets for privacy compliance.
Secure PDF Redactor - Permanently redact sensitive information from PDFs by flattening them into images.
Face Age Detector - Analyze facial landmarks to estimate biological age and skin health metrics for personal reference.
Real-Time Emotion Detector - Detect and visualize facial emotions in real-time to analyze reactions.
Eye Contact AI Trainer - Improve your presentation skills by tracking how well you maintain eye contact with the camera.
AI Posture Corrector - Receive alerts when you slouch to maintain healthy ergonomics using AI posture tracking.
Voice Pitch Analyzer - Visualize your voice pitch and frequency in real-time for singing and speech training.
LUFS Meter for Streaming - Ensure your audio meets loudness standards for Spotify and YouTube to avoid compression.
Game Ping Test & Jitter - Test your connection to game servers to predict lag and check stability before playing ranked matches.
Mandi Chest Piece Lucky Draw - Fairly pick a random winner from a list of names for contests or giveaways.
Offline QR File Transfer - Securely transfer files between devices using QR codes without internet or Wi-Fi.
Universal 'AirDrop' (P2P WebRTC) - Transfer files between any OS (Android to iPhone, Windows to Mac) instantly via a local P2P WebRTC bridge. No uploads to servers; the file streams directly from device memory to device memory.
Pro Controller 'Snap-Back' & Jitter Map - Goes beyond 'Stick Drift.' This precision tool measures the 'Snap-Back'—the speed and accuracy at which a joystick returns to center—and maps the raw polling jitter to identify failing potentiometers in Hall Effect vs. ALPS sensors.
Browser-Based GPU Stress & Thermal Test - Uses WebGPU to push your graphics processor to its limit within the browser. It monitors frame-rate stability to detect if your laptop is 'thermal throttling' (slowing down due to heat) without needing to install heavy software.
Web-Haptic Feedback Vibration Designer - Uses the Vibration API and Gamepad API to test and design custom haptic patterns for your phone or controller. It checks the 'Haptic Resolution'—how fast your motor can start and stop—to grade the hardware quality.
Personalized HRTF (Spatial Audio) Profiler - Every ear is shaped differently. This tool uses your webcam to map your ear shape and generates a custom HRTF (Head-Related Transfer Function) profile you can use in 2026 spatial audio players to make 3D sound feel truly immersive.
Invisible Image Watermarker - Embed invisible copyright data into your images that survives compression but remains undetectable to the human eye.
IEM/Earbud 'Seal' & Isolation Quality Test - Plays a series of out-of-phase low-frequency tones. By asking the user to identify when the sound 'centers,' it calculates the quality of your earbud seal (passive isolation), which is critical for 2026 spatial audio accuracy.
Touchpad 'Dead Zone' & Gesture Heatmap - Paint your touchpad surface to find unresponsive areas and verify if your hardware supports 2026's new 5-finger productivity gestures.
USB-C Power Delivery 'Handshake' Sniffer - Connect your charger through your laptop. This tool uses the WebSerial API to read the power negotiation profile, telling you if your cable is actually rated for 100W/240W or if it's 'fake' and bottlenecking your charging speed.
WebGPU VRAM & Thermal Stability Stressor - Uses the WebGPU API to stress-test your graphics memory. It monitors frame-rate stability to detect if your laptop is 'Thermal Throttling'—slowing down due to heat—often caused by hidden AI agent background tasks.
Amsler Grid (Macular Degeneration) - A specialized grid test used to detect early signs of Macular Degeneration. Users focus on a center dot to see if the surrounding straight lines appear wavy or missing—a critical self-check for anyone over 50.
Instagram Follower Insights - Safely analyze your Instagram data export locally in your browser. Discover who doesn't follow you back, identify your secret fans, and audit your social graph without ever entering your password.
Saliva Hydration Index - Estimate hydration status by analyzing saliva characteristics through image analysis of mouth swabs.
Pursuit Tracking Test - Test smooth pursuit eye movement tracking ability with various target patterns for attention assessment.
Rhythm Synchronization Test - Test your ability to synchronize with musical rhythms and measure your rhythm perception and coordination.
Eye Tracking Cognitive Load - Estimate cognitive load through pupil dilation tracking during mentally demanding tasks using webcam.
Postural Sway Analyzer - Measure postural stability and balance through webcam analysis of center of pressure movement patterns.
Binaural Beat Brainwave Generator - Generate binaural beats for brainwave entrainment—Delta, Theta, Alpha, Beta and Gamma frequencies for focus, sleep, meditation and relaxation.
Capillary Refill Timer - Time capillary refill as a bedside clinical screening tool. Normal refill is under 2 seconds; prolonged refill may indicate dehydration or circulatory compromise.
Contrast Sensitivity Function Test - Measure the minimum contrast your eyes can detect at different spatial frequencies—a more sensitive vision test than standard Snellen acuity for early disease detection.
Digital Dementia Risk Screening - Cognitive screening tests for memory, executive function, and attention to identify potential early markers of cognitive decline in a private, browser-based format.
Duochrome Vision Balance Test - Refraction balance test using red/green chromatic aberration to verify optimal corrective lens prescription accuracy and binocular vision balance.
Critical Flicker Fusion Threshold - Measure the frequency at which a flickering light appears steady—CFF is a sensitive biomarker for fatigue, medication effects, and early visual system changes.
Hand Tremor Stability Analyzer - Quantify hand tremor amplitude and frequency using your device accelerometer or webcam mouse tracking. Track essential tremor, medication effects, or fine motor skill improvement.
Headphone Driver Rattle Test - Detect damaged or rattling headphone drivers using sweep tones and specific sub-bass frequencies. Identify mechanical defects causing distortion before warranty expires.
IV Drip Rate Tapper / Calculator - Calculate and verify IV infusion drip rates by tapping along with the drops. Calculates drops per minute, mL/hour, and infusion duration for nursing and paramedic use.
NFC Data Ghost Eraser - Read and erase data from NFC tags directly from your browser using the Web NFC API. Privacy-focused tool for wiping smart tags before disposal or re-use.
Optical Lens Law Depth Calculator - Apply the thin lens equation to calculate focal length, image distance, and object distance for optics education, camera lens physics, and vision science.
Oxygen Tank Duration Calculator - Calculate remaining oxygen supply duration from tank pressure, volume, and patient flow rate in L/min. Essential tool for EMS, home care, and anesthesiology planning.
Pupillary Light Reflex Tester - Test pupillary response to light changes using your screen as a stimulus. Identifies potential RAPD (Relative Afferent Pupillary Defect) and tracks autonomic reactivity.
PWM Flicker Eye Health Scanner - Detect monitor PWM flicker rates that cause eye strain and headaches. Uses a visual detection test to identify monitors with high-frequency PWM dimming incompatibility.
Screen-to-Eye Lux Calibrator - Estimate your screen brightness in lux at eye level and compare against Dr. Andrew Huberman circuit thresholds for healthy circadian photon exposure optimization.
Sleep Apnea Breathing Pattern Analyzer - Record and analyze breathing rhythm during rest using your device microphone. Flags irregular breathing intervals, potential apnea events, and snore frequency patterns.
Tongue Coating Health Scanner - Analyze tongue coating color and distribution via webcam for Traditional Chinese Medicine (TCM) patterns and standard clinical diagnostics including hydration status.
Webcam Heart Rate (rPPG) - Measure your heart rate without contact using remote photoplethysmography (rPPG) via your webcam. Detects subtle facial skin color changes from blood pulse waveforms.
HRV Biofeedback Trainer - Free online HRV biofeedback trainer using webcam. Measure heart rate variability in real-time and learn resonance breathing for stress reduction and optimal wellness.
Display Color Gamut Visualizer - Free display color gamut visualizer. Compare monitor color coverage against sRGB, DCI-P3, and Adobe RGB standards.
Color Harmony CVD Designer - Design accessible color palettes for users with color vision deficiency. Test color harmony and create designs that work for everyone including red-green color blindness.