Ready to convert
Enter a number and click Convert// convert numbers between any base instantly
Convert numbers between Binary, Octal, Decimal, Hexadecimal and any custom base (2–36) instantly in the browser. Free, no sign-up required.
Ready to convert
Enter a number and click ConvertType or paste the number you want to convert in the input field.
Choose the base your number is currently in — Binary, Decimal, Hex, or a custom base.
Check the bases you want, click Convert, and copy any result with one click.
A number base converter transforms a number written in one positional numeral system into another. Common bases include Binary (2), Octal (8), Decimal (10), and Hexadecimal (16) — all essential in programming, networking, and hardware design.
All bases from 2 to 36. Digits above 9 are represented as letters A–Z (case-insensitive). This covers Binary (2), Octal (8), Decimal (10), Hexadecimal (16), Base32, Base36, and everything in between.
Yes — prefix your number with a minus sign (e.g. -FF in hex or -1010 in binary) and the tool will handle the sign correctly across all output bases.
No. You can type ff, FF, or fF — the converter normalises input before processing. Output is always uppercase for bases above 10.
The tool uses JavaScript's built-in parseInt and toString, so it safely handles integers up to 253−1 (about 9 quadrillion in decimal). For cryptographic or very large numbers, a dedicated big-integer library is recommended.
All conversion logic runs entirely in your browser with no server calls. Once the page has loaded you can use it completely offline.
It copies every visible result to your clipboard as plain text, with one label-value pair per line — ideal for pasting into notes or documentation.
Whether you're reading memory dumps, working with network masks, designing hardware registers, or simply exploring number theory, switching between numeral systems is a daily task for developers. This free online Number Base Converter handles it instantly — no installation, no account, no limits.
Binary (Base 2) is the native language of computers — every piece of data ultimately lives as a sequence of 0s and 1s. Hexadecimal (Base 16) is a compact shorthand for binary: each hex digit maps to exactly four bits, making it ideal for colour codes, memory addresses, and checksums. Octal (Base 8) was popular in older Unix systems for file permissions, and each octal digit represents three bits. Decimal (Base 10) is the everyday number system humans use, and it's the default input for most programming contexts.
Beyond the common four, this tool supports any base from 2 to 36. Base 36 (digits 0–9 plus A–Z) is frequently used to generate short, URL-safe unique identifiers. Base 32 is a common encoding for TOTP secrets in two-factor authentication apps. Simply choose "Custom base…" and enter any value between 2 and 36.