Features
What it does
A converter has one job, so the features below are the ones that make that job faster or make the answer more trustworthy. There is nothing here you need an account for.
Every unit at once
Type a value and it lands in all 602 units of the category simultaneously. No target to choose, no second page load when you guess wrong about which unit you wanted.
Precision you control
Dial significant figures from 1 to 15, and switch between automatic, scientific, engineering and plain notation. Plain drops the thousands separators and the exponent so the value pastes straight into a spreadsheet or a code editor.
Fractions where fractions are read
Length and typography can show the nearest sixty-fourth alongside the decimal, because that is how a tape measure and a type scale are actually divided. A value that is not exactly representable is labelled approximate rather than presented as though it were exact.
Answers without leaving the keyboard
Press / or Ctrl+K (⌘K on a Mac) and type a whole conversion — “12 kg to lb”, “3/8 in in mm”, “100c to f”. The answer appears in the palette itself, so the fastest path from question to number never involves a page load.
Links that carry the whole view
The address bar tracks the value, the source unit, the precision, the notation and the fraction toggle. Send the link and the recipient sees exactly what you saw — not the default view of the same page.
Works with no JavaScript, and no network
Pages are rendered complete on the server, so the conversion table is correct before any script runs. Scripting only updates the numbers already on screen. Visited pages keep working offline.
Exact number-base conversion
Binary, octal, decimal, hex and every base from 2 to 36, computed with exact integer and rational arithmetic instead of floating point — so a 64-bit value keeps every digit, and a repeating expansion is labelled rather than silently truncated.
Checkable factors
Every category page publishes the factor table it converts with, each anchored to the SI base unit and derived from its published definition. The arithmetic is auditable rather than something you have to trust.
Your values never leave the page
No accounts, no advertising, nothing to install. Conversions happen in your browser, and the analytics that counts page views is given the page path with the query string stripped — so the value you typed is never part of what gets reported.
Light and dark, without the flash
The theme is applied before the first paint, so switching to dark mode or reloading in it never shows a white flash first. Your choice persists across visits.
