Integer base converter

Client

Convert a whole-number string between any radices 2 and 36. Pairs with the hex (bytes) tool when you need UTF-8 or raw nibbles instead of a single integer.

Integers only — use digits 0-9 and letters a–z (case ignored) up to the radix. Values use BigInt in your tab so long hex strings stay exact.
?

Any radix from 2 to 36. Digits 0-9, then a-z for 10-35. For base 16 you may include a leading 0x.

Input

Output (base 16)

Common use cases

  • Turn a long hex id from a log into binary or base-36 for another system.
  • Compare 0x-prefixed strings with a pure digit view by switching the input base to 16.
  • Check that a pasted token only uses valid digits for the radix before scripting around it.

Common mistakes to avoid

  • Treating the tool as float math

    No decimal point, scientific notation, or fractional bases—integers and whole-number radices only.

  • Assuming every Unicode digit works

    Only ASCII 0-9 and a–z (case ignored) are accepted, per the usual Definition of radix for JavaScript parseInt and BigInt-style expansion.

  • Forgetting two’s-complement for binary machine words

    Binary here is a mathematical radix, not fixed-width two’s complement. For bit-field semantics, mask and document width yourself.

FAQ

What is the largest value?

The implementation uses BigInt, so the limit is practical memory in your tab, not 53-bit floats.

How do I prefill from a link?

Use ?q= for the digit string and optional &from=10&to=16 (2–36). For long strings, use qb= (Base64 UTF-8) like other single-field tools on Toolcore.

Is this the same as the hex text tool?

The hex encode page works on raw UTF-8 bytes; this page converts a whole integer literal between number bases. Pick hex encode for bytestreams, and this for radix math.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • binary to hex converter online
  • decimal to base 36 big integer
  • radix converter 2 to 36 browser
  • parse hex 0x to binary string

More tools

Related utilities you can open in another tab—mostly client-side.