Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal bases.
About This Tool
Number Base Converter is a free online tool that converts numbers between binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base from 2 to 36. Enter a value in any base and all other representations appear immediately. JavaScript BigInt ensures precision for very large numbers.
The converter is built for developers, students, and engineers who work with different numeral systems regularly. Binary and hexadecimal are fundamental to low-level programming, computer architecture, memory addressing, and color code manipulation. The ability to enter any custom base up to 36 supports niche encoding systems like Base32 (TOTP) and Base36 (URL shorteners).
Number Base Converter is most useful for computer science students learning numeral systems, embedded systems engineers working with register values in hex, web developers decoding color codes, and anyone verifying number base conversions in algorithm or cryptography work.
How to Use
- 1
Enter your number and select its base (binary, octal, decimal, hex, or custom).
- 2
View the converted values in all other bases simultaneously.
- 3
Copy any result with the copy button.
- 4
Enter a custom base (e.g., base 32 or base 36) for specialized encoding schemes.
- 5
Use the binary output to understand bit patterns for low-level programming or hardware work.
Features
All Common Bases
Convert between binary (2), octal (8), decimal (10), and hexadecimal (16) with a single input.
Custom Base Support
Enter any base from 2 to 36 for conversions beyond the standard formats.
BigInt Precision
Uses JavaScript's BigInt for accurate conversion of very large numbers without precision loss.
Simultaneous Output
See all base conversions at the same time — no need to convert one pair at a time.
Common use cases
- ›Convert decimal values to hexadecimal for CSS color codes, memory addresses, or bytewise data.
- ›Translate binary bit patterns to decimal or hex for embedded systems and microcontroller work.
- ›Convert between bases for algorithm problems, competitive programming, or CS coursework.
- ›Use custom base 32 or 36 conversion for encoding schemes in authentication or URL shorteners.
FAQ
What number bases are supported?
Binary (2), Octal (8), Decimal (10), Hexadecimal (16), and any custom base from 2 to 36.
Does it support large numbers?
Yes, it uses BigInt internally so you can convert very large numbers accurately.
What is hexadecimal used for?
Hexadecimal (base 16) is widely used in computing for memory addresses, color codes (#RRGGBB), bytewise data representation, and processor instruction encoding.
Can I enter letters for bases above 10?
Yes. For bases above 10, digits are represented by letters (A=10, B=11, ... Z=35). For example, hex uses 0-9 and A-F.
What are custom bases used for?
Custom bases are used in specific encoding schemes: Base 32 for Crockford encoding and TOTP tokens, Base 36 for URL shorteners and compact ID generation.