Number Base Converter Online – Binary, Octal, Hex, Base 36

How to use the All Number Converter

Find the field for the base your number is written in: decimal, hex, binary or octal. For any other base from 2 to 36, pick it in the Custom list.

Type the number in that field; spaces, commas and underscores are ignored.

Read the value in every other field; they all update as you type.

Copy the representation you need.

A number base converter for every common radix

This number base converter takes one value and shows it in all the bases developers usually need, so you do not have to chain several single-purpose converters together. Type the number in the field of the base you are starting from, and read decimal, hexadecimal, octal and binary at a glance, plus a custom base of your choice (2 to 36) and the bit length.

What you get for each number

Decimal (base 10):      255
Hexadecimal (base 16):  FF
Binary (base 2):        11111111
Octal (base 8):         377
Custom (base 36):       73
8 bits · 1 byte

Enter 255 in the decimal field, FF in hex, 377 in octal or, with the custom base set to 32, 7V, and the other fields show the same values, because they are all the same quantity. The converter holds one number at a time; spaces, commas and underscores inside it are ignored.

The input bases

Binary (2), octal (8), decimal (10), hex (16): the everyday programming bases. Each has its own field, and prefixes such as 0b, 0o and 0x are accepted in the field of the matching base.
Base 32: positional notation with the digits 0–9 and A–V. Select it in the Custom list.
Base 36: digits 0–9 and A–Z, the largest base that fits in the ten digits plus the Latin alphabet, and the one the Custom field starts with. Letters are not case sensitive, so zz and ZZ both mean 1295.

Base 32 here is not Base32 encoding

With the custom base set to 32, the result is a plain number written in radix 32, like JavaScript's (255).toString(32). It is different from the RFC 4648 Base32 encoding used for secrets and file names, which encodes bytes with the alphabet A–Z and 2–7. For that, use the Base32 encoder.

Why base 36 is handy

Base 36 is the most compact case-insensitive alphanumeric form of a number. 1234567890 shrinks to KF12OI, which is why it is popular for short IDs, ticket codes and URL slugs. You can decode such an ID by typing it into the Custom field with base 36 selected.

Bit length and grouped binary

The bit length, shown with the byte count next to the options, tells you how many bits the value needs: 255 needs 8, 256 needs 9, and 1234567890 needs 31, so it fits in a signed 32-bit integer. Setting Group digits to Nibbles pads the binary field to a multiple of four bits so you can match each block to a hex digit.

Negative numbers and fractions

You can enter values like -3.75. The converter then shows decimal (-3.75), hex (-3.C), octal (-3.6), binary (-11.11) and the custom base (-3.R in base 36). The bit length counts only the whole-number part without its sign, so it reads 2 bits here.

When to use a single converter instead

If you only ever convert between two bases, a dedicated page such as decimal to binary or hex to decimal puts those two fields first and explains the method for that pair step by step.

Frequently asked questions

What bases does the converter support?

Any base from 2 to 36. Decimal, hex, binary and octal have their own fields, and a fifth field takes whichever base you pick from the Custom list (36 by default). You can type in any of them and the rest update.

What digits does base 36 use?

The ten digits 0–9 followed by the 26 letters A–Z, so Z is 35 and 10 in base 36 equals 36. Upper and lower case letters are treated the same.

Is the base 32 output the same as Base32 encoding?

No. With the custom base set to 32, this tool writes the number in radix 32 using 0–9 and A–V. Base32 encoding (RFC 4648) converts bytes of data with the A–Z, 2–7 alphabet and padding, which is a different process.

How large can the numbers be?

Whole numbers of any size are converted exactly, because the tool uses arbitrary-precision integers. Fractions are shown to 20 digits after the point in each base.

What does bit length mean?

It is the number of binary digits needed to write the value without leading zeros. A value with bit length 32 or less fits in an unsigned 32-bit integer.

All Number Converter