Number
When you need to turn a decimal number into binary or hex, or read a hex color or byte value back in decimal, this base converter shows all four representations from a single input. Pick the input base, type a number, and the binary, octal, decimal and hex values update live — each row copies with one click. Input is flexible: plain numbers like 255, prefixed values like 0xFF (hex), 0b1010 (binary) or 0o777 (octal), and digit separators such as 1010_1100 with underscores or spaces are all accepted. The bit view at the bottom groups the binary into 4-bit nibbles and shows how many bits the value needs, which is handy for flags, bitmasks and shift operations. Internally it uses JavaScript's BigInt, so even integers larger than 32-bit or 64-bit convert exactly without losing digits — useful for computer-science homework, programming, electronics and network (subnet) math. Everything is calculated entirely inside your browser; the numbers you enter are never uploaded, stored or sent to a server.
How to use
- Choose the input base (2 / 8 / 10 / 16) in the toolbar.
- Type a number — prefixes like 0xFF, 0b1010 or 0o777 and separators (spaces or underscores) are accepted.
- Binary, octal, decimal and hex appear instantly, with a bit view (4-bit groups plus bit count) below. Use "Copy" on any row. Nothing you enter is sent anywhere.
FAQ
Are the numbers I enter uploaded anywhere?
No. All base conversion runs in your browser with JavaScript. The numbers you enter are never uploaded, stored, or sent to a server.
Can I use prefixes like 0xFF or 0b1010?
Yes. A prefix matching the selected base (0x for hex, 0b for binary, 0o for octal) is accepted with or without it. Digit separators such as underscores, spaces or commas (e.g. 1010_1100) are ignored as you type.
Does it handle numbers larger than 64-bit?
Yes. It uses JavaScript's BigInt (arbitrary-precision integers), so integers larger than 32-bit or 64-bit convert exactly without losing precision. The bit count reflects the actual number of bits.
What does the bit view show?
It shows the binary representation grouped into 4-bit nibbles, plus the number of bits the value needs. That's handy for checking flags, bitmasks and shift operations (it does not pad with leading zeros to a fixed width).
Can it convert negative numbers or fractions?
Negative integers work with a leading minus sign. It does not produce fixed-width two's-complement (e.g. 11111111 for 8-bit) — negatives are shown signed. Fractions (digits after a decimal point) are not supported; this tool focuses on integer base conversion.
Is the digit grouping included when I copy?
No. The display groups digits for readability, but "Copy" gives you the plain value without separators, so you can paste it straight into code or documents.