Number Base Converter
ConvertConvert numbers between binary, octal, decimal, and hexadecimal in real time. Great for programming, networking, and low-level debugging.
Runs entirely in your browser. Nothing is uploaded.
Binary · Octal · Decimal · Hex
Low-level work means moving constantly between bases: a permission mask in octal, a colour or memory address in hex, a bit pattern in binary, and a plain decimal number in the middle of it all. Typing into any one field here updates the other three immediately, so you can read the same value four ways instead of converting one step at a time and losing your place.
How to convert between number bases
- 1
Pick a starting base
Type into the binary, octal, decimal, or hexadecimal field — whichever you have.
- 2
Read the other three
Every other base updates live from the value you entered.
- 3
Copy what you need
Grab any single representation with one click.
Good to know
- Handles all four common bases: base 2, base 8, base 10, and base 16.
- Invalid digits for the chosen base are rejected as you type, so a stray character does not silently produce a wrong answer.
- Hex input is case-insensitive, and you do not need to include a `0x` prefix.
- Conversion is arithmetic in the page: nothing is sent anywhere.
What people use it for
- Reading a hex colour, memory address, or byte value as decimal
- Working out a Unix file-permission mask in octal
- Checking a bitmask or flag value bit by bit in binary
Frequently asked questions
Which bases are supported?+
Binary (2), octal (8), decimal (10), and hexadecimal (16). Type in any field and the others update instantly.
Can it handle very large numbers?+
Yes: it uses BigInt internally, so arbitrarily large integers convert precisely.
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