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ChaosLens

Free browser-based tools for image processing, health calculations, keyboard and display testing, random generation, charts, unit conversion, and everyday utilities. Many tools run locally in your browser, keeping files and inputs on your device.

All Tools

90 tools available. Select one to open it here.

Arc Diagram Maker

Build an arc diagram from source, target, weight, and group data, then inspect, style, and export the result.

Centimeter, Inch, and Feet-and-Inches Converter

Convert centimeters, total inches, and feet plus inches in either direction.

Image Splitter

Split images locally by crop boxes, draggable lines, grids, or fixed pixel tiles.

Mac Keyboard Test

Test a Mac keyboard one key at a time to see which standard keyboard events the browser recognizes and find keys that are not tested or captured.

Macro Calculator

Calculate daily protein, fat, and carbohydrate targets from calories, weight, and your preferred allocation rule.

Mouse Single- and Double-Click Test

Click the test area to distinguish separate clicks, valid double-click intervals, and suspected switch bounce.

Random Number Generator

Generate random integers or decimals within a custom range, with quantity, uniqueness and sorting controls.

Carbohydrate Needs Calculator

Enter daily calories, weight, goal, training volume, and carbohydrate percentage to estimate daily carbohydrate grams, calories, and a reference range.

BMI Calculator

Calculate BMI, a healthy weight range, and adult screening categories from your height and weight.

Increase Image File Size

Increase JPG, PNG, and WebP file sizes locally without changing pixel dimensions.

Keyboard CPS Test

Choose a duration and key mode, tap quickly, and review average CPS, the one-second rolling peak, and valid key count.

List Randomizer

Paste or upload a list, clean blank and duplicate lines, then shuffle the remaining items into a new order.

Ideal Weight Calculator

Compare four classic ideal-weight formulas and the adult BMI reference range using your height and sex.

Keyboard Rollover Test

Choose a combination to press at once, then hold several keys to see which key events the browser receives at the same moment, the maximum simultaneous count, and possible missing keys.

Random Item Picker

Paste a list of items, pick one or more entries at random, and review the remaining items and draw history.

Touchscreen Test

Use the touch grid to check touch-point count, trace continuity, edge coverage, and possible dead zones on a touchscreen.

Body Fat Goal Calculator

Enter your current weight, body fat percentage, and daily calorie deficit to estimate your target weight, amount of fat you need to lose, and the time frame.

Coin Flip Simulator

Choose how many flips to run, simulate a fair coin, and review the running counts, observed shares, and recent rounds.

Keyboard Chatter Test

Choose a key and complete repeated press-and-release cycles to flag intervals below a threshold and review the suspected chatter rate and stability.

Black Level Test

Step through near-black patches from 1 to 32 and record the gray level that first separates from a pure-black background on your display.

Dice Roller

Choose the number of dice, sides, modifier, and rounds, then inspect individual rolls, totals, visual dice, and batch distribution.

Keyboard Dropout Test

Hold a target key and analyze steady-state browser auto-repeat intervals to find suspected long gaps and judge whether the sample is sufficient.

Wedding Seating Chart Maker

Add your guest list and table assignments to create a wedding seating chart, review assignments, choose a design, and print or export it as PDF.

Waist-to-Hip Ratio Calculator

Enter sex, waist circumference, and hip circumference to calculate WHR and view common WHO adult reference cutoffs and measurement guidance.

Waist-to-Height Ratio Calculator

Enter waist circumference, height, and optional age to calculate WHtR, view a continuous adult reference band, and compare waist size with half your height.

Backlight Bleed Test

Use a full-screen black display to inspect edge and corner bright spots, then record the conditions, severity, and affected regions.

Body Fat Calculator (U.S. Navy Method)

Estimate body fat percentage, fat mass, and lean mass from sex, height, weight, and body circumferences using the classic U.S. Navy method.

Keyboard Latency Test

Press a normal key repeatedly to estimate the scheduling delay from the browser event timestamp to the start of JavaScript handling, then review the median, P95, and sample distribution.

Yes or No Decision Generator

Enter a question and receive a random yes, no, or optional maybe, with weights, batch statistics, and history.

TDEE Calculator

Enter sex, age, height, weight, and activity level to estimate BMR, TDEE, and a maintenance-calorie range, with steps and training minutes to check the activity factor.

Wedding Menu Card Maker

Build a wedding menu from courses and descriptions, choose a coordinated design, optionally personalize it with guest names and meal selections, then print or export PDF.

Wedding Place Card Maker

Import guest names, tables and meal choices to create printable wedding place cards in multiple styles and export a print-ready PDF.

Calorie Deficit Calculator

Enter TDEE, select fat loss, maintenance or muscle gain mode, and instantly calculate target calories, daily difference, theoretical weekly change and planning range.

Wedding Table Number Maker

Generate matching wedding table numbers or custom table names, preview multiple styles, and print each sign or export the set as PDF.

Caffeine Intake Calculator

Enter drink servings, volume, and caffeine per serving to estimate daily caffeine, source shares, and an adult reference comparison.

Sugar Intake Calculator

Enter daily calories and sugar sources to calculate added sugar, free sugars, and their share of energy.

Bingo Number Caller

Call bingo numbers without repeats from 1–75, 1–90, or a custom range.

Weight loss time calculator

Enter your current weight, target weight, and weekly weight loss rate to estimate the weeks required, target date, and planning range.

Keyboard Polling Rate Test

Alternate between two ordinary keys to estimate the upper bound of the browser's non-repeat key-event frequency, then inspect P10 gaps, stability, and sample distribution. The result cannot certify hardware polling rate.

Wedding Bar Menu Maker

Enter signature cocktails, beer, wine and non-alcoholic drinks to create a printable wedding bar menu.

Random Letter Generator

Generate one or more random English letters while controlling case, repeats, excluded letters, and sorting.

Wedding Budget Calculator

Enter your total wedding budget, category percentages and actual spending to calculate planned amounts, variances and remaining budget.

Wedding Buffet Label Maker

Enter dish names, descriptions and dietary tags to generate printable flat or tent wedding buffet labels.

Wedding Cake Serving Calculator

Enter guest count, cake shape, display-cake coverage and buffer to estimate tier sizes, servings and supplemental portions.

Wedding Catering Calculator

Enter guest count and portion assumptions to estimate wedding meal plates, appetizers, sides, desserts, late-night food and vendor meals.

Wedding Checklist Generator

Choose your wedding date to generate a dated planning checklist, mark tasks complete and add your own tasks.

Wedding Dance Floor Size Calculator

Enter guest count, expected dancing share and space-per-dancer assumptions to estimate a practical wedding dance floor size.

Wedding Day Timeline Generator

Enter ceremony and reception timing to generate a practical wedding-day schedule from getting ready through the final song.

Wedding Favor Tag Maker

Enter one or more favor-tag messages, choose copies and tag size, then generate printable wedding favor tags on A4 or Letter paper.

Random String Generator

Choose a length, quantity, and character set to create one or more random strings directly in your browser.

Typing Speed Test

Choose a practice passage from ChaosLens's eight default languages and measure net speed, gross speed, accuracy, uncorrected errors, corrections, and completion progress locally in your browser.

Water Intake Calculator

Estimate a daily beverage range from your weight, activity and heat or sweating, while keeping the total-water Adequate Intake (AI) reference separate.

Wedding Invitation Maker

Enter couple names, date, ceremony time, venue and RSVP details to create a printable wedding invitation.

Wedding Photography Shot List Maker

Choose essential wedding photo moments, add custom shots and print a photographer-ready wedding shot list.

Wedding QR Code Sign Maker

Enter a wedding website, RSVP, registry or photo-upload URL to generate a printable QR code sign.

Wedding Seating Capacity Calculator

Enter room dimensions, reserved floor area, circulation buffer and space-per-guest assumptions to estimate wedding seating capacity.

Wedding Vendor Tip Calculator

Enter vendor costs and your chosen percent, fixed or per-person tip rules to calculate a wedding tip-envelope plan.

JavaScript Keyboard Event Tester

Focus the test area and press keys to inspect the keydown, keyup, key, code, location, repeat, modifier, composition, and timing data that this browser receives.

Random Hex Generator

Generate random hexadecimal data by exact byte count or HEX character count, with a clear view of character length, byte equivalent, and random bits.

Keyboard Repeat Rate Test

Hold a chosen key to measure the first auto-repeat delay, the steady repeat interval, and repeats per second reported by the browser, then review interval stability. The result reflects operating-system and browser events, not the keyboard's hardware polling rate.