Hex to binary converter

Invalid characters—letters outside A–F, spaces, underscores, or an empty 0x—raise a clear invalid_input error instead of a silent wrong bit string. Students checking homework, embedded engineers reading register dumps, and API clients normalizing memory addresses all need the same deterministic path: no network, no random seeds, no wall-clock dependence.

How to call the API and what comes back

The value may include a leading 0x or 0X; after that only characters zero through nine and A through F (any case) are allowed. Send a JSON body with one required string field hex (aliases value, text, n, and input). Absolute length is capped at sixty-four hex digits so Worker and browser responses stay bounded. On success the response echoes the trimmed input, sets hex to the uppercase digit string without prefix, hex_lower to the lowercase form, prefixed to a canonical 0x plus uppercase digits, had_prefix to whether the client sent 0x, binary to the minimal base-2 bit string without leading zeros (except for zero), binary_padded to the four-bits-per-digit expansion that preserves nibble alignment, base_from sixteen and base_to two, digit_count to the number of hex digits, bit_count to the length of the minimal binary string, message to a one-line English summary, and steps to an ordered list that records prefix handling, validation, nibble mapping, and the final binary. Failed validation—missing hex, empty digits after 0x, spaces or underscores, characters outside the hex alphabet, or more than sixty-four digits—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price. Prefer binary when you need a compact bit string for code, and binary_padded when you need fixed-width nibbles for teaching or bitfield diagrams.

Practical tips, limits, and related searches

Prefer sending a string even when the value looks numeric: bare numbers are accepted only when they are non-negative integers written with decimal digits zero through nine, which is a convenience for small dumps, not a second radix. Do not embed spaces, commas, or underscore separators; strip them in your client before calling if your source uses grouped nibbles. Sixty-four hex digits cover two hundred fifty-six-bit integers, which is enough for most wide machine words and truncated hash displays; longer strings are rejected rather than silently truncated. Prefer this capability when the source is already known to be hex and you only need the bit string; if you must convert to decimal as well, call the matching hex-to-decimal tool in a second step. When teaching, pair examples: 0xFF maps to 11111111, 0xA maps to 1010, and G or 0x yields invalid_input so students see the error path. This landing targets people searching for a hex to binary converter, hexadecimal to binary calculator, or base-16 to base-2 tool; it is not a color picker, not a hex-to-decimal converter (use that sibling when you need base-10 integers), and not a general arbitrary-base calculator with a from-base parameter. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when you fuzz invalid digits. Round-trip checks are easy: convert a known value such as 0xFF by hand or with another trusted library and confirm that binary matches 11111111, then confirm that changing one letter to an invalid character flips the response to invalid_input with a message that names the bad digit.