Utility Tools

Precise online stopwatch with lap times, plus a live world clock: analog dials for major cities with digital readouts and UTC offsets below.

Test every key on your keyboard online: see key codes, modifier states and a rolling press log. Nothing to install.

Test mouse buttons, wheel and tracking online. Live coordinates, click counters per button and a movement trail on canvas.

Fullscreen pure-color tests to find dead pixels and check uniformity, plus screen info: resolution, pixel ratio and color depth.

Calculate BMI (WHO/CN categories), body fat percentage (U.S. Navy tape method) and basal metabolic rate (Mifflin-St Jeor) with daily calorie needs.

Play white, pink or brown noise and pure-tone sound waves for sleep, focus or tinnitus relief. Generated live by Web Audio.

Free mortgage calculator for commercial, housing-fund and mixed loans: monthly payment, total interest and per-part breakdown. Fixed or decreasing repayment, common-rate presets, works by loan amount or home price.

Turn any image into a playable jigsaw puzzle (3×3 to 5×5) with a timer and move counter. Click two tiles to swap them.

Play a two-octave piano with your computer keys, mouse or a real MIDI keyboard. Web Audio synthesis with selectable waveforms.

Draw a floor plan: grid-snapped walls with auto dimensions, doors, windows and PNG export.

Add as many countdowns as you need — each with its own name, duration and progress ring. Presets like 5 or 25 minutes add in one click, timers run independently, and a triple beep plays when one reaches zero.

Convert between units of length, weight, area, volume, temperature, speed, data storage and time — with an instant table of the value in every unit of the category.

Merge several PDFs in any order, extract a page range into a new file, delete pages, or rotate every page by 90/180/270 — files never leave the page.

Compute the interval between two dates (years/months/days, total days, weekdays), add or subtract days, weeks, months or years — with an optional business-day mode — and turn a birthday into an age plus a countdown.

Start a local preview to confirm your camera and microphone work: live resolution and frame rate, a mic level meter that warns when nothing is picked up, device switching and a PNG snapshot.

Record a screen, application window or browser tab with optional system / tab audio and microphone mixing, pause and resume while recording, then preview and download the result as a WebM video.