Expanding hexadecimal to binary is the reverse of grouping bits into hex digits, and it is essential when you need to inspect individual bits, set bitmask flags or read register layouts. This converter turns any hex value into its full binary bit string by expanding each digit into a four-bit nibble.
How it works
Hexadecimal is base 16 and binary is base 2, and 16 equals 2 to the fourth power. That power-of-two relationship means each hex digit maps to a unique group of exactly four binary digits. The conversion is therefore a simple per-digit lookup: A becomes 1010, F becomes 1111, 5 becomes 0101, and the results are joined together in order.
No decimal intermediate is needed. The tool reads each hex character, looks up its four-bit pattern in a fixed table, and concatenates. It then offers a trimmed view with leading zeros removed (the true numeric value) and a nibble-aligned view that keeps every group of four bits intact.
Example
Convert AF. The digit A expands to 1010 and F expands to 1111. Concatenated, that is 10101111, which equals 175 in decimal. The nibble-aligned view displays it as 1010 1111 so the correspondence with the two original hex digits is obvious.
Tips and notes
You can include spaces, underscores or a leading 0x for readability; all are stripped before conversion. The nibble-aligned view is especially helpful when mapping hex register dumps back to individual control bits. Everything is processed locally in your browser, so no data leaves your device.