The Big Bin Toolbox is a free collection of fast, privacy-first online tools that run entirely in your browser — no signup, no installs, and nothing you enter is ever sent to a server. From word games and calculators to converters, generators, and developer utilities, every tool is built to just work. Browse all 14 tools below, available in 40 languages.
Every tool here is plain JavaScript running on your own device. There is no backend, which means the letters you unscramble, the dates you track, the passwords you generate and the JSON you paste never travel anywhere — not to a server, not to a log file. You can confirm that yourself in about ten seconds with your browser's network tab open.
The formulas behind each calculator, including what they can't tell you, are written out in full on the methodology page. If you'd rather see the tools used in context, the guides walk through complete scenarios with worked numbers.
Word & Text Tools
Unscramble, count, generate — master every word.
Word Unscrambler
Type in jumbled letters, get every valid word. Scrabble, Wordle, and more.
Launch Tool →Word & Character Counter
Count words, characters, sentences. Reading time, keyword density, readability scores.
Launch Tool →Lorem Ipsum Generator
Classic, Hipster, Corporate and more. Generate placeholder text in any style.
Launch Tool →Personal Life Management
Track your health, plan your life, and understand your body better.
Period Calculator
Track your cycle, predict your next period, and find your fertile window with visual calendar.
Launch Tool →Due Date Calculator
Estimate your due date, track trimester milestones, and count down to your baby's arrival.
Launch Tool →BMI Calculator
Calculate your Body Mass Index, see your healthy weight range, and check your BMI category.
Launch Tool →Age Calculator
Your exact age in years, months, days. Birthday countdown, planetary ages, and life stats.
Launch Tool →Calculators
Crunch numbers for sleep, mortgages, and life.
Security & Privacy
Protect yourself with strong passwords and secure tools.
Design Tools
Pick colors, generate QR codes, and create visual assets.
Developer Tools
Format, convert, and debug with precision.
How these tools get used together
Most of them were built as sets, because real questions rarely stop at one calculation.
Trying to conceive, pregnancy, and the first year
The longest chain here. The Period Calculator finds the fertile window by counting backwards from your next period — not forwards from your last, which is the mistake almost everyone makes. The Due Date Calculator then takes that date through to a due date and reports gestational age the way a midwife does, so the number on screen matches the number in your notes. Once the baby arrives, the Age Calculator takes over, because every appointment for the next two years is specified in weeks while every relative asks in months.
Buying a home
The Mortgage Calculator gives you a monthly payment, which is the least interesting number it produces — the amortisation table showing that your first payment is three-quarters interest is the one that changes decisions. The Unit Converter handles the square-feet-to-square-metres problem that every property listing creates (the factor is nearly eleven, not three). And the Age Calculator answers the question people tend to run only after signing: how old will I be when this is paid off?
Locking down your accounts
The Password Generator draws from the browser's cryptographic RNG and reports honest entropy — including for passphrases, where most strength meters overstate by a factor of nearly two by counting characters instead of words. The QR Code Generator solves the social half of the problem: its WiFi mode lets you run a genuinely strong network password that guests connect to by pointing a camera, instead of dictating it across a room.
Shipping a small website
In the order the decisions arrive: the Color Picker builds the palette and checks it against WCAG contrast thresholds before you build twelve components on top of a failing grey. Lorem Ipsum stress-tests the layout with deliberately uneven filler. The Word Counter confirms your meta description fits the space Google gives it. The JSON Formatter untangles the API response — locally, which matters when it contains an API key. Then the QR Code Generator turns the finished URL into something printable.
Word games
The Word Unscrambler is most useful when you treat it like a chess engine — after the game, on the racks you got wrong, until you need it less. Its filters are the real tool: length, starts-with, ends-with, contains and wildcards for blank tiles, checked against the right dictionary for Scrabble, Words With Friends or Wordle. The Word Counter's letter-frequency breakdown is a quick way to see why the tile distribution is weighted the way it is.