Runway

See your balance on any day of the year — and how much you can actually spend.

🔒 Private: your numbers never leave this device

Scenario each one keeps its own balance, settings and items

Open file

Your starting point

Upload spreadsheet

Your privacy

  • Your numbers never leave this device. There are no accounts, no tracking, no analytics and no ads. Whatever you enter is saved only in this browser. The site never receives it.
  • That's enforced, not just promised. The page has a browser security rule (a Content Security Policy) that stops it from sending data anywhere. It only loads its own files.
  • Lock it with a passphrase if you like. Your saved plans, and any files you save, are then encrypted with AES-256. The passphrase isn't stored anywhere, so if you forget it, nobody can get your plans back.
  • Keep a backup. Clearing your browser data deletes your plans, and some browsers (Safari, for example) clear data for sites you haven't visited in a while. Use Save to file to keep a copy or move a plan to another device.
  • What the host can see. Like any website, the host (GitHub Pages) sees that someone visited, such as an IP address. It never sees what you type.
  • Check it yourself. The source code is public.
Spreadsheet format

Upload a CSV or Excel file with a header row. Only name, amount and day are needed; the rest is optional. Column names are matched loosely (“Bill”, “Due”, “Cost” all work).

name,amount,day,type,frequency
  Rent,1450,1,bill,monthly
  Car payment,389,15,bill,monthly
  Phone,85,22,bill,monthly
  Car insurance,640,2026-03-10,bill,yearly
  Paycheck,1800,2026-11-14,income,biweekly

day can be a day of the month (1–31) or a full date. For weekly, every-2-weeks and yearly items, use a real date (any past or upcoming one). Bills due on the 29th–31st fall on the last day of shorter months. frequency: monthly (default), weekly, biweekly, twice a month, yearly, once. Anything marked income, pay, paycheck or deposit counts as money in; everything else is a bill.

“Safe to spend that day” is the most you could take out on that day and still never drop below your cushion for the rest of the look-ahead window. Near the end of the window it's optimistic, since it can't see bills past the end.

Balance over time

Balance Safe to spend that day Cushion Tap a day for details · drag to move · pinch or scroll to zoom

What happens when (days in view)

DateItemAmountBalance after