Everyday utilities
Small tools for everyday jobs: dates and time zones, percentages and prices, unit conversions, word counts, fair random picks and generators for QR codes, barcodes and passwords.
The tools
See every ZapKit toolDates & time
5 toolsAge, days between dates, countdowns, time zones and Unix timestamps.
- Age calculatorExact age in years, months and days, and days to the next birthday.
- Date difference calculatorDays, weeks, months and weekdays between two dates; add or subtract days.
- Countdown timer (days until)Live countdown in days, hours, minutes and seconds to any date.
- Time zone converterOne date and time shown in several cities, daylight saving included.
- Unix timestamp converterEpoch time to date and back, in seconds or milliseconds.
Percent & price
3 toolsPercentages every way round, discounts and profit margins.
Unit converters
7 toolsLength, weight, temperature, area, volume, speed and data size.
- Length convertercm, inches, feet, metres, km, miles and more.
- Weight converterkg, pounds, grams, ounces, stones and tola.
- Temperature converterCelsius, Fahrenheit and Kelvin.
- Area converterSquare feet, square metres, acres, hectares and gaj.
- Volume converterLitres, millilitres, gallons, cups, spoons and cubic units.
- Speed converterkm/h, mph, m/s, knots and ft/s.
- Data size converterBytes, KB, MB, GB, TB, KiB, MiB, GiB and bits.
Text tools
3 toolsWord and character counts, reading time, SMS length and case conversion.
Random & games
4 toolsRandom numbers, a name-picking wheel, dice and a coin toss, all fair.
- Random number generatorRandom whole or decimal numbers in any range, with or without repeats.
- Name picker wheelSpin a wheel of names to pick a random winner fairly.
- Dice rollerRoll up to ten d4, d6, d8, d10, d12, d20 or d100 dice.
- Coin flipToss a virtual coin once, 10 or 100 times, with a running tally.
Generators
4 toolsQR codes, barcodes, strong passwords and UUIDs, made in your browser.
- QR code generatorQR codes for links, text, Wi-Fi, email, phone and SMS, as SVG or PNG.
- Barcode generatorCode 128, EAN-13 and UPC-A barcodes with check digits, as SVG or PNG.
- Password generatorStrong random passwords made in your browser, with a strength meter.
- UUID generatorRandom v4 and time-ordered v7 UUIDs, plus a UUID checker.
Frequently asked questions
Do these tools upload what I type?
No. Every utility runs in your browser. Text you count, passwords you generate and QR codes you make stay on your device; only harmless settings are kept in the page address so you can share them.
Are the random tools really fair?
Yes. The random number generator, name picker, dice and coin all use your browser's cryptographic random generator, with corrections so no outcome is more likely than another.
Which time zone do the date tools use?
Your device's own time zone. The time zone converter lets you compare any zones, with daylight saving applied for the date you pick.
Can I use the QR codes and barcodes commercially?
Yes, there are no limits or watermarks. Retail product barcodes need a number licensed from GS1, but the codes you make here are yours to print.