Binary / Decimal / Hex Converter
Convert numbers between binary, octal, decimal, hexadecimal, or any custom base 2–36.
Processed locally in your browser. Nothing you enter is uploaded or stored.
- All four common bases in view at once — change any one and the rest follow.
- A custom-base field for any base 2–36, e.g. base32 or base36 for short-URL/ID encoding.
- Handles negative numbers and fractional values (e.g. `10.5` or `-FF`), not just non-negative integers.
- Handy for bitmasks, colour values, permissions and byte-level work.
- Runs in your browser.
Why this is private
- Processed locally in your browser. Nothing you enter is uploaded or stored.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Converts a number between binary, octal, decimal, hexadecimal, or any custom base from 2 to 36 — edit any field and the others update instantly.
How to use it
- 1Type a number into any of the four fields, or set a custom base (2–36) and type into that field.
- 2The other fields update automatically.
Examples
Decimal to hex
Input
255
Output
FF
Decimal to binary
Input
10
Output
1010
Decimal to base36
Input
71
Output
1Z
Frequently asked questions
What people use it for
Read a hex colour channelConvert `FF` or `3A` to decimal to reason about an RGB value.
Work out a Unix file permissionConvert between octal (`755`) and its binary bits.
Decode a bitmask or flag valueSee a decimal flag total in binary to identify which bits are set.
Check a hex offset from a hex dumpConvert a file offset to decimal to jump to it.
Encode or decode a base36/base32 short IDConvert a numeric ID to a compact base36 string (or back) for a short URL or token.
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- JSON parse errors explained: 'Unexpected token', 'Expected comma or brace', and the restWhat each common JSON error message actually means, the usual cause, and how to find the spot fast using line and column.
- How to format JSON (and actually understand the errors)JSON looks like a JavaScript object but follows stricter rules. Here's what those rules are and how to read the errors when they're broken.
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Ready to use Binary / Decimal / Hex Converter?
Binary / Decimal / Hex Converter