Hex to decimal converter

Invalid characters—letters outside A–F, spaces, underscores, or an empty 0x—raise a clear invalid_input error instead of a silent wrong number. Students checking homework, embedded engineers reading register dumps, and API clients normalizing color or 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, decimal to the integer as a JSON number when it fits Number.MAX_SAFE_INTEGER or as a decimal digit string when it does not, decimal_string always to the full decimal representation, base_from sixteen and base_to ten, digit_count to the number of hex digits, message to a one-line English summary, and steps to an ordered list that records prefix handling, validation, place-value expansion, and the final decimal. 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.

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 hashes truncated for display and for wide machine words; 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 decimal integer; if you must convert binary or octal as well, use a multi-base tool. For values larger than Number.MAX_SAFE_INTEGER the decimal field is a string so no mantissa rounding can corrupt low bits—always prefer decimal_string when you need a stable textual form across languages. When teaching, pair examples: 0xFF maps to two hundred fifty-five, 10 without prefix maps to sixteen (not ten), and G or 0x yields invalid_input so students see the error path. This landing targets people searching for a hex to decimal converter, hexadecimal to decimal calculator, or base-16 to base-10 tool; it is not a color picker, not a DMS angle converter, 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 deadbeef by hand or with another trusted library and confirm that decimal_string matches, then confirm that changing one letter to an invalid character flips the response to invalid_input with a message that names the bad digit.