Number Base & Radix Converter
Convert numbers between binary, octal, decimal, hex, base58, and text with BigInt precision. Your work stays on this device whenever possible.
How to use Number Base & Radix Converter
- Set "Input Number System" to Decimal, Hexadecimal, Binary, Octal, Base58 (Bitcoin) or "ASCII / UTF-8 Text".
- Type the number into "Value" (it starts as 255); hex may begin with 0x, binary, octal and hex may contain spaces or underscores, and decimal may contain commas.
- Press "Convert All Bases" or hit Enter to fill cards for decimal, hexadecimal, binary, octal and Base58, plus "Decoded UTF-8 Text" when the bytes are readable.
- Leave "Group bits/nibbles with spaces" ticked for readable groups, or clear it for unbroken digits.
- Use "Sample 64-bit Hash" to load DEADBEEFCAFE1234, or "Clear" to start over.
Worked example
Choose ASCII / UTF-8 Text and enter Hi. With grouping on, Decimal shows 18,537, Hexadecimal 48 69, Binary 100 1000 0110 1001 (the leading zero bit is dropped), Octal 44 151 and Base58 6Wc. The Decoded UTF-8 Text card shows Hi, and the status line says Converted successfully (15 bits).
When to use this tool
- Reading a file permission mask in octal alongside its binary bits.
- Expanding a hex colour or hash into decimal for a script.
- Seeing which large integer a short ASCII tag represents.
Important limitations
Conversions use native JavaScript BigInt arithmetic to eliminate 64-bit IEEE-754 precision limits for large integers. Fractional radix conversions reflect finite decimal precision.
Comparing alternatives
Other options for number base & radix converter include RapidTables, BinaryHexConverter, CyberChef.
ToolkitPoint is not affiliated with those services.
Frequently asked questions
How large a number can it handle?
It uses arbitrary-precision BigInt arithmetic, so there is no 64-bit ceiling and a 256-bit hash converts exactly. Because the input is treated as a number, leading zeros are dropped, so 0x00FF shows FF. Keep that in mind for fixed-width identifiers.
Can it convert negative or fractional values?
No. A minus sign or a decimal point is rejected. The error text mentions two's complement modes, but no such mode exists here, so convert the absolute value and apply your own signing convention.
What kind of Base58 is this?
The Bitcoin alphabet, which omits 0, O, I and l, applied to the whole value as one integer. Real Base58Check handles leading zero bytes specially and adds a checksum, so this cannot be used to validate an address.
What does the text mode do?
Text is encoded to UTF-8 bytes and those bytes are read as one big-endian number, so the word Hi becomes 18537. The Decoded UTF-8 Text card appears only when the number's bytes form valid UTF-8.
What does grouping change?
With grouping on, binary is split in fours from the right, hex in pairs, octal in threes, and decimal gets thousands commas. It changes only the display, so remove the spaces yourself if you copy a value into code.