Tools
Handy tools you can use without logging in. What you type is processed in your browser and is mostly never sent to the server.
No matching tool.
Calculate & convert
Calculator
A calculator from basic arithmetic to trigonometry and logs, plus VAT, discount, percent, bill-splitting, loan-interest and amount-in-words calculators, and unit/date expressions such as “5km + 300m to mi” or “today + 100 days”. Everything is computed on this page and history stays in this browser.
Unit converter
Convert length, weight, temperature, area and volume, including traditional Korean units such as pyeong, geun, don and ja.
Exchange rates & alerts
Convert between 30 currencies at the European Central Bank reference rates, and get an email when a rate you care about is reached.
Color Converter
Convert HEX, RGB, CMYK and HSL color codes to each other, and check text/background contrast (WCAG) and palette combinations.
Quote & statement maker
Enter your items to get a document preview with supply value, VAT and total (with the amount in Korean words), then print it or save it as a PDF. Nothing you enter is sent to a server.
Salary & Payroll Calculator
Take-home pay after Korean social insurance and income tax, weekly-holiday allowance, severance pay and unemployment benefit. Uses that year's rates; nothing you enter leaves this browser.
Real Estate Calculators
Korean brokerage fee caps, home acquisition tax, jeonse-monthly rent conversion and LTV/DSR loan limits. Reference calculations using that year's rules; nothing you enter leaves this browser.
Location Data Converter
Convert between GPX, KML and GeoJSON, transform WGS84 and Korean TM / UTM-K coordinates, switch coordinate notations, and compute distance and bearing. Files and coordinates never leave this browser.
Ruler & level
Use your phone or monitor as a ruler (calibrated with a bank card), check level with the tilt sensor, and measure angles with an on-screen protractor. Measurements never go to a server.
Excel & CSV Analyzer
Open CSV or xlsx files to search, filter and sort, see per-column statistics, and a simple pivot (group totals) with bar charts. Files are processed only in this browser and never uploaded.
Use offline too
When turned on, tool pages and the files they need are saved on this device so the calculation and conversion tools work without internet. You can also install just the tools on your home screen.
Saving needs a few MB after you turn it on (large tools add more when used). Login information is never saved, and you can turn it off any time. Tools that need the server, such as the QR maker, web page checker, My IP and secret notes, do not work offline.