Number Base
Bin, oct, dec, hex
What is Number Base?
Convert numbers between any two bases from 2 to 36 (digits 0-9 plus letters a-z). Uses BigInt so very large numbers round-trip without loss, supports ignoring whitespace and underscores in the input, and includes a swap button to flip the direction of conversion.
How do I use Number Base?
- Pick From and To bases.
- Type the input value.
- Read the converted output.
When should I use Number Base?
Base Convert is for non-standard bases. For the common bin/dec/hex/oct set, Binary ↔ Decimal has a simpler UI with all four visible at once.
Which bases are supported?
Any base from 2 (binary) to 36 (digits 0-9 plus a-z). Use this for non-standard bases like base-5 or base-32.
What alphabet is used?
Standard 0-9, a-z (lowercase). Toggle uppercase if your target system expects 0-9, A-Z. Base-32 and base-64 have their own alphabets — use the dedicated tools for those.
Does it handle very large numbers?
Yes — BigInt under the hood, so there is no integer overflow. Fractions are limited to 20 digits of precision.
Is my file uploaded anywhere?
No. Everything runs in your browser. Your files never leave your device, and there is no server component for this tool.