Number Base Converter
Binary, octal, decimal, hex and everything between.
Runs entirely in your browser — your data is never uploaded to any server.
How it works
- Enter a numberWith a 0x or 0b prefix, or set the base yourself.
- We convert itInto every common base at once.
- Read the bit patternGrouped into bytes for easy scanning.
What this tool does
- Any base from 2 to 36, in and out
- Prefix detection for 0x, 0b and 0o
- Binary shown grouped into bytes
- Large values handled exactly using BigInt — no precision loss
Frequently Asked Questions
Arbitrarily large. Conversion uses BigInt, so values well beyond 2^53 stay exact instead of silently rounding.
Yes, with a leading minus sign. It does not show two’s-complement representations, which depend on a word size you would have to specify.
Whole numbers only. Fractional binary and hex are a different problem.
It uses all ten digits and all 26 letters, which makes it the most compact plain-text encoding for a number — common in short IDs.
Privacy and security
Your input is processed by JavaScript running inside your browser. Nothing you paste is sent over the network, logged, or stored — which is what makes this safe to use with production data. If you want to check this yourself: open your browser’s developer tools, switch to the Network tab, and use the tool — you will see no request carrying your file or input leave the page.