BIN · 2 // enter a number above

OCT · 8 // enter a number above

DEC · 10 // enter a number above

HEX · 16 // enter a number above

custom (2–36) → // enter a number above


              curl -sX POST 'https://api.whittly.dev/v1/base/convert' \
  -H 'Authorization: Bearer $WHITTLY_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"input":"255","fromBase":10,"toBases":[2,8,16]}'


              const res = await fetch('https://api.whittly.dev/v1/base/convert', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer ' + apiKey,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ input: "255", fromBase: 10, toBases: [2, 8, 16] }),
});
const data = await res.json();


              const { data } = await axios.post(
  'https://api.whittly.dev/v1/base/convert',
  { input: "255", fromBase: 10, toBases: [2, 8, 16] },
  { headers: { Authorization: 'Bearer ' + apiKey } }
);

// probulk conversionpro·history syncproupgrade →

// about this tool

Computers operate in binary (base 2), but humans prefer decimal (base 10). Hexadecimal (base 16) is used in color codes, memory addresses, and character encodings. Octal (base 8) appears in Unix file permissions. This tool converts between any of these — or any custom base from 2 to 36.

// when to use

Convert a hex color code to decimal RGB values
Understand binary representations of integers
Convert Unix file permission octal values
Work with any numeric base in custom encoding schemes

// faq

What is the maximum number supported?

The converter uses JavaScript BigInt for large numbers, so there is no practical upper limit. Numbers with hundreds of digits are supported.

Why do hex values use letters A–F?

Hexadecimal needs 16 distinct digits but the decimal system only has 10 (0–9). Letters A through F represent the values 10 through 15. This convention dates back to early computing and is now universal.

// related tools

// about this tool

// when to use

// faq