QKitBoxNumber base converter
Type in any base and every other representation updates at once — binary, octal, decimal, hex, or any custom base 2–36.
Type into any field — all others update. Supports negative numbers and validates digits against each base.
How it works
Everything parses through BigInt, so numbers far beyond the 64-bit limit convert correctly — useful for reading hex color data, binary flags or large identifiers. Digit validity is enforced per base: binary rejects a 2, hex accepts a–f.
Frequently asked questions
Why BigInt?
Regular JavaScript numbers lose precision past 2^53. BigInt converts correctly at any magnitude — hex dumps and bit flags routinely exceed that.
Which digits are valid in base 36?
0–9 then a–z, so base 36 is the densest human-readable encoding — the same alphabet short URL services use.
Written and maintained by Steven Huang · Last reviewed October 29, 2026.