No ads, no tracking. Runs entirely in your browser — nothing leaves your device unless you opt into sync.
Find a percentage of a number, what % one number is of another, and more.
Calculate a discounted sale price or a marked-up selling price instantly.
Calculate your exact age in years, months, and days.
Calculate the difference between two dates with a live countdown to future dates.
Every US federal holiday and observance for any year, with observed dates and calendar export.
A printable monthly and yearly calendar for any year, with holidays marked, ISO week numbers and your own events.
Convert times across time zones instantly. Multi-zone view with DST-aware offsets and a visual timeline.
Find sunrise, sunset, solar noon, and twilight times for any location and date.
Convert between cooking, length, weight, temperature, and volume units.
Plot your child's height, weight, and head circumference on WHO and CDC growth charts with percentile and adult height prediction.
Convert fractions to decimals and back, with millimetres alongside and the nearest 1/16, 1/32 or 1/64 mark.
Convert numbers to Roman numerals and back, with subtractive notation and input validation.
Simplify a width/height into a ratio like 16:9, or find a missing dimension from a ratio and one known side.
Convert shoe sizes between US, UK, EU, and Japan (JP), plus foot length in cm, for men, women, and kids.
Calculate running pace, time, or distance from the other two, with race presets and a splits table.
Calculate weighted GPA from courses by grade and credit hours, with +/- grades and a cumulative mode.
Find the best bedtime for a wake-up time, or wake-up times for a bedtime, based on 90-minute sleep cycles.
Calculate trip fuel cost from distance, efficiency, and price, or find your actual MPG or L/100km.
Four-function and scientific calculator with parentheses, exponents, and keyboard input.
Find what an appliance costs to run per day, month, and year from its wattage and your rate.
Estimate a due date from your last period, conception date, or a known due date, with weekly milestones.
Cubic yards and bag counts for a slab, footing, column, or flight of stairs.
Estimate gallons of paint for a room from its dimensions, doors, windows, and coats.
How many pieces fit in a sheet of plywood, fabric, or vinyl — with saw kerf, mixed rotation, and a cutting diagram.
Boxes of tile, plank, or laminate for any number of rooms — with areas left out and waste set by the lay pattern.
The AWG size a run actually needs — checked against NEC ampacity and voltage drop, with a full copper and aluminum reference table.
Generate secure random numbers, flip coins, and roll dice.
Generate strong random passwords and passphrases with entropy-based strength estimates.
Generate random usernames and display names from adjective-noun combinations.
Calculate sales tax and total price. Add tax to a price or extract it from a total.
Calculate tip amount, total bill, and per-person split instantly.
Split a bill between people with per-item custom shares and proportional tax/tip.
Convert pay between hourly, weekly, biweekly, monthly, and annual with overtime, estimate take-home, and compare offers.
Calculate monthly payments, total interest, and view a full amortization schedule.
Compare renting against buying over time — mortgage, taxes, maintenance, appreciation and the opportunity cost of your down payment.
See how your savings grow with compound interest and optional monthly contributions.
Track income and expenses by category, set monthly budgets, manage savings goals, and view spending trends.
Log hours by project and task, view weekly and monthly summaries, and export for billing.
Your personal recipe manager. Save, organize, and search recipes. Group them into boards like "Weeknight Dinners" or "Mom's Recipes."
Scale recipe ingredient quantities up or down. Handles fractions, mixed numbers, and ranges.
Plan your meals for the week, build a reusable recipe library, and generate a grocery shopping list.
Manage your standing grocery list, flag sale items and deals, track shopping trips, and get smart restock suggestions.
Work out how many pizzas to order for a group, with slices per person, leftovers and a topping split.
Calculate your Body Mass Index from height and weight. Metric and imperial.
Estimate calories burned during exercise by activity, duration, and body weight.
Stopwatch with lap tracking and countdown timer with audible alarm.
A private daily journal kept in your browser. One entry per day, full-text search, Markdown export, and optional sync to your own Google Drive.
A private, offline-first task manager. Create tasks with due dates and priorities, organise into lists, and track subtasks.
Generate placeholder text by paragraphs, sentences, or words. Classic Latin, English-like, or Hipster Ipsum.
Count words, characters, sentences, paragraphs, and estimated reading time.
Compare two blocks of text and highlight every insertion, deletion and change — by line, word or character.
Write Markdown and see it rendered live, with tables, task lists and fenced code. Copy the HTML or export a standalone file.
Parse cron expressions into plain English, preview the next scheduled run times, and browse common patterns.
Calculate IPv4 subnet details from CIDR notation — network address, broadcast, host range, mask, and subnet splitting.
Decode, verify and sign JSON Web Tokens. Inspect header, payload and claims, check a signature with HS/RS/ES algorithms, or build and sign a new token.
Convert between CSV and JSON formats. Handles RFC 4180 quoting, custom delimiters, type inference, and table preview.
Test and debug regular expressions with live match highlighting, capture group extraction, and flag toggles.
Generate SHA-256, SHA-384, and SHA-512 cryptographic hashes from text.
Compute a file’s SHA-256, SHA-384, SHA-512, SHA-1 or MD5 checksum and compare it against a published value. Nothing is uploaded.
Convert numbers between binary, octal, decimal, and hexadecimal.
Convert between Unix timestamps and human-readable dates. Live clock included.
Generate v4 (random), v5 (deterministic), and v7 (time-ordered) UUIDs.
Format and prettify JSON, or minify it for production. Validates JSON instantly.
Generate TypeScript interfaces or type aliases from pasted JSON. Merges mixed arrays, quotes awkward keys, and resolves name collisions.
Convert text between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case, and more.
Encode text to Base64 or decode Base64 back to plain text.
Encode text for URLs or decode percent-encoded strings back to plain text.
Generate QR codes for URLs, text, Wi-Fi, contacts, email, and SMS. Customize colors and download as SVG or PNG.
Encode special characters to HTML entities and decode entities back to plain text. Supports named, decimal, and hexadecimal formats.
Crop, rotate, resize, and compress images to AVIF, WebP, JPEG, or PNG. Fully client-side — your image never leaves the browser.
Vectorize PNG, JPG, WebP, or GIF images into clean, scalable SVG. Trace logos, icons, and line art fully in your browser.
Generate harmonious color palettes from any base color. Complementary, analogous, triadic, tetradic, and more.
Preview colors, palettes and images with protanopia, deuteranopia, tritanopia or achromatopsia, and find pairs that stop being distinguishable.
Convert colors between hex, RGB, HSL, HSV and OKLCH. Gamut indicator, Display P3 output, tonal scales, harmonies, and a WCAG contrast checker.
Backing, batting, binding, borders, sashing and cut sizes for quilt shapes — six calculators in one, in inches and yards.
Spread increases or decreases evenly across a knitting or crochet row, written out as an instruction with both stitch counts checked.
How much yarn a knitting or crochet project needs, from your own gauge — plus skeins to buy, yarn substitution and foundation chains.
Use your phone as a digital bubble level. Check if any surface is level or plumb using your device's accelerometer.
Live GPS coordinates, altitude, speed, and compass heading from your device.
Find upcoming solar and lunar eclipses with local visibility. See if an eclipse is visible from your location.
Moonrise, moonset, transit, phase, illumination and moon age for any location and date.
Tide times and heights for US coastal stations, with the full tide curve and the year's biggest tides.
Find Hohmann transfer windows between any two solar system bodies, with countdown, timetables, and ΔV estimates.
Discover your natal chart: sun sign, moon sign, rising sign, and planet placements.
Find out how old your dog is in human years, accounting for size and breed.
Find out how old your cat is in human years using AAHA guidelines.
Printable 5x5 bingo cards — classic B-I-N-G-O numbers or your own words and phrases. Up to 24 per batch, PNG download, print view, shareable link.
Slide and merge numbered tiles on a 4x4 grid with the arrow keys or a swipe. Best score saved locally.
Endless downhill skiing. Dodge trees and rocks, hit ramps for air, and share the seed so someone else can ski the same slope.
Falling-notes piano game. Play fourteen public-domain tunes — short or full-length — on a real keyboard or five arcade lanes, by touch, mouse or typing.
Steady click from 20 to 300 BPM, with tap tempo, eight time signatures, an accented downbeat and subdivisions. Shareable as a link.
Play a note and see which one it is and how many cents sharp or flat, with presets for guitar, bass, ukulele and violin and an adjustable reference pitch.
Play a steady sine, square, triangle or sawtooth from 20 Hz to 20 kHz, with a note picker and a left/right channel test. For tuning by ear and testing speakers.
Classic Snake on a 20x20 grid. Steer with the arrow keys or a swipe, eat apples to grow, and go faster with every three you catch.
Play Minesweeper with Beginner, Intermediate and Expert boards, or set your own grid size and mine count.
Play Sudoku with four difficulty levels, pencil marks, undo, conflict highlighting and a daily puzzle. Your game is saved as you play.
Create drag-and-drop tier list rankings. Add items as text or images, customize tiers, and export as PNG or shareable file.
Color-mixing painting game: mix realistic paints to match a target palette, then brush-paint a coloring page. Works offline.