Number Base Converter
Convert between binary, octal, decimal, and hexadecimal — 100% local processing
About Base Converter
Numbers can be written in different bases. Decimal (base 10) is what people use daily, binary (base 2) is how computers store values, octal (base 8) appears in Unix file permissions, and hexadecimal (base 16) is a compact way to write binary data such as colors, memory addresses, and byte values.
Enter a number in one base and this converter shows it in the others. It is useful when reading low-level output, working with bit masks, or checking a value against a specification.
Common use cases
- Converting a hex value from a debugger or log into decimal.
- Viewing the binary bits behind a flag or bit mask.
- Translating octal permission values such as 755.
- Checking your manual base conversion homework or code output.
Frequently asked questions
- Why is hexadecimal so common in programming?
- One hex digit maps exactly to four bits, so a byte is always two hex digits, which makes binary data compact and easy to read.
- What does the 0x prefix mean?
- It marks a number as hexadecimal in many languages, for example 0xFF equals 255. The converter also recognizes 0b for binary and 0o for octal.
- Can it handle very large numbers?
- Yes. Conversion uses arbitrary-precision integer arithmetic (BigInt), so values too large for a normal 64-bit number still convert correctly.