Hexadecimal · Base 16 → Base 2

Hex to Binary Converter

Q: How do you convert hex to binary?

Replace each hex digit with its 4-bit binary pattern and concatenate them. F becomes 1111, A becomes 1010, and so on.

Q: What is FF in binary?

FF becomes 1111 1111, an 8-bit value of all ones.

Q: How many bits is one hex digit?

Exactly four bits, called a nibble, because 16 equals 2 to the 4th power.

Updated: June 2026

Going from hex to binary is the mirror of grouping nibbles: instead of merging four bits into a digit, you expand each hex digit back into its four-bit pattern. It is the fastest way to inspect the exact bits behind a register value, a flag set or a color channel.

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The digit-by-digit method

Replace each hexadecimal digit with its fixed four-bit pattern and write them side by side in the same order. No arithmetic, no carries — just substitution. Take 3A7:

3 → 0011
A → 1010
7 → 0111
result → 0011 1010 0111

Joined together that is 001110100111. You can drop the leading zeros of the very first digit if you want the shortest form (11 1010 0111), but keeping every nibble four bits wide makes the byte boundaries obvious.

The hex-to-nibble table

Hex	Bits	Hex	Bits
0	0000	8	1000
1	0001	9	1001
2	0010	A	1010
3	0011	B	1011
4	0100	C	1100
5	0101	D	1101
6	0110	E	1110
7	0111	F	1111

This is the same lookup used for binary-to-hex, just read in the opposite direction. Knowing it both ways lets you flip between the two bases instantly.

Reading the bits

Once a hex value is expanded, you can see exactly which flags are set. For example a permission byte 0xB4 becomes 1011 0100, telling you bits 7, 5, 4 and 2 are on. This is invaluable when debugging hardware registers, network packet headers or bitfield-packed configuration where each individual bit has its own meaning.

Where it helps

Decoding control and status registers in embedded and driver development.
Inspecting individual flag bits inside a packed hex value.
Teaching how hex shorthand maps onto real binary storage.
Preparing bit patterns for masks, shifts and logical operations.

Frequently asked questions

How do you convert hex to binary?

Expand each hex digit into its four-bit pattern and place them in order. 3A7 → 0011 1010 0111.

What is FF in binary?

FF is 1111 1111 — eight set bits, one full byte.

How many bits is one hex digit?

Exactly four, because 16 = 2⁴. That clean ratio is why hex and binary interconvert without arithmetic.

Can I drop leading zeros?

Yes for the final number, but keep four bits per digit while converting so the columns stay aligned.