FAQ
Can it handle very large numbers?
Yes. It uses BigInt, so integers beyond the double-precision 2^53 limit stay exact.
Are decimals and negatives supported?
Yes. The sign is preserved and fractional parts convert to the target base.
Which bases are supported?
Six: 2, 8, 10, 16, 36 and 64. Type in any one and the other five update live. The base-64 digit set is 0-9A-Za-z+/, which is not the same as RFC 4648 Base64 encoding.
About this tool
The input accepts six bases — 2, 8, 10, 16, 36 and 64. Pick the base your number is written in and the other five are produced at the same time: there is no "from" and "to", the same value is simply shown six ways.
Base 36 and base 64 are not everyday bases, but they have concrete uses: base 36 (0-9 plus A-Z) shortens long numbers and is common in short links, order IDs and share codes; base 64 (0-9, A-Z, a-z, +, /) has more digits so the string is shorter still. Note that base 64 here means re-expressing a number in a 64-digit system, which is not RFC 4648 Base64 encoding (that slices a byte stream into 6-bit groups). The two results are not interchangeable — use the Base64 tool to encode text.
Integers are computed with BigInt, so values beyond 253 (9007199254740992) stay exact instead of drifting like a normal JS number. That matters for snowflake IDs and 18–19 digit primary keys: a plain Number starts losing digits after the 16th and silently produces a different hex string.
Fractional parts are converted to 24 significant digits. Some decimal fractions repeat forever in binary (0.1 for example), so any base conversion can only be approximate — this tool will not truncate them to zero, but it cannot make them exact either. The input only accepts characters valid in the selected base; pasting a number with a 0x prefix or inner spaces is rejected and highlighted, so strip the prefix first.