Number Base Converter (Binary, Hex, Decimal)
Convert numbers between binary, octal, decimal, hexadecimal and any base 2–36 — 100% in your browser.
About Number Base Converter (Binary, Hex, Decimal)
Enter a number and see it instantly in binary, octal, decimal and hexadecimal, plus any custom base from 2 to 36. The base is detected automatically from 0x, 0b and 0o prefixes, or you can set it explicitly, and underscores are allowed as digit separators.
Conversions use arbitrary-precision BigInt math, so very large values stay exact — no floating-point rounding. Everything runs locally in your browser; nothing is uploaded.
How to use Number Base Converter
- Choose the source and destination bases or use a recognized 0x, 0b or 0o prefix.
- Enter an integer and compare the converted binary, octal, decimal or hexadecimal output.
Limitations and common mistakes
For example, decimal 255 is hexadecimal ff and binary 11111111. Prefix detection is useful, but confirm how a leading zero is interpreted by your destination language.
The converter uses integer arithmetic and BigInt support. It does not interpret fractional numbers, signed machine-word encodings or floating-point bit patterns automatically.
The tool processes its input locally on your device. Read our privacy policy for analytics, storage and network details.
Decimal to hex and binary
255
binary 11111111 · octal 377 · hex ff
Prefix with 0x, 0b or 0o and the input base is detected automatically.
Frequently asked questions
Which bases are supported?
Binary (2), octal (8), decimal (10) and hexadecimal (16) are always shown, plus any custom base from 2 to 36.
Does it handle very large numbers?
Yes. It uses BigInt arbitrary-precision arithmetic, so large values convert exactly without floating-point errors.
How does auto-detect work?
A 0x prefix is read as hexadecimal, 0b as binary and 0o as octal; anything else is treated as decimal. You can also pick the input base manually.
Is my data uploaded anywhere?
No. All conversion happens locally in your browser.
For related tasks, explore Timestamp Converter and Hash Generator. Their guides explain the different inputs, assumptions and output formats.