Number Base Converter
Enter a number, pick its base, and see all four bases at once.
Binary
Octal
Decimal
Hexadecimal
Developer tool
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal - instantly and exactly.
All tools
Related Tools
More developer and data utilities.
How To Use This Tool
Type a number, choose which base it is in (decimal, binary, octal, or hex), and the other three bases update instantly. Use the copy buttons to grab any result.
Common Uses
Reading hex color codes and memory addresses, working with bitmasks and flags, debugging, and learning how number systems relate.
Why This Tool Is Useful
Programmers constantly move between bases - hex for colors and addresses, binary for bitwise logic, decimal for everyday math. This converter shows all of them at once and uses big-integer math, so large values stay exact.
Accuracy And Privacy
All conversion runs locally with arbitrary-precision integers, so there is no rounding error and nothing is sent to a server.
FAQ
Does it handle very large numbers?
Yes. It uses big-integer math, so even numbers far beyond 64 bits convert exactly without rounding.
What bases are supported?
Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16).