WebToolArcUse this result with confidence
The allowed digit set depends on the source base
A digit must be smaller than the base it belongs to: binary accepts only 0 and 1, octal stops at 7, decimal stops at 9, and bases above ten usually continue with letters. Rejecting an invalid digit is safer than guessing what the user meant. Keep the source base visible when sharing a value so strings like 1010 are not interpreted in the wrong radix.
Integer and fractional conversion use different place values
Whole-number digits use nonnegative powers of the base, while digits after the radix point use negative powers. If a workflow includes fractional values, preserve the radix point and choose an explicit output precision because many fractions repeat in another base. An integer-only converter should not silently truncate a fractional source value.
Large integers need exact arithmetic rather than floating-point shortcuts
JavaScript Number cannot represent every integer exactly beyond its safe range. Long identifiers, bit masks, cryptographic-looking test values, and packed binary fields should use arbitrary-precision integer arithmetic such as BigInt when the base conversion is intended to be exact. Compare a round-trip back to the source base when exact digits matter.
Signedness and bit width are separate from radix notation
A hexadecimal string can be treated as an unsigned magnitude or interpreted as a signed two’s-complement bit pattern. The base alone does not determine that meaning. For low-level programming values, record the intended bit width and signedness separately so converting FF to decimal does not silently switch between 255 and −1.