Number Base Converter
Convert between binary, octal, decimal and hexadecimal. Handles arbitrarily large integers with exact precision and readable digit grouping.
Examples and how it works
Base conversion writes the same integer in another radix. Hexadecimal 41 is decimal 65. Reading byte 41 as UTF-8 produces A instead; use the Hex-to-text tool for character decoding.
Base 16 → base 10
- Input
- 41
- Output
- 65
Select the input radix first. This is an integer conversion; treating a byte sequence as one number is different from decoding text.
Done
Number Base Converter
How to use
- 1
Enter a number
Type the number you want to convert and choose its base.
- 2
Select the base
Pick the original base from binary, octal, decimal or hexadecimal.
- 3
Check the results
Conversions to every other base appear instantly.
Features
- Convert between binary, octal, decimal and hexadecimal
- BigInt-backed: exact results even for huge integers
- Converts to every base instantly as you type
- Your number is never sent to a server
Use cases
Programming and debugging
Check bit operations or decode the hexadecimal values that appear in memory dumps and error logs.
Networking and device config
Relate MAC addresses (hex) to IP addresses (decimal) and convert values for device settings.
Color codes and RGB
Match web color codes such as #FF8800 with their decimal RGB values.
Details
Base conversion rewrites a number between binary (0 and 1), octal (0-7), decimal (0-9) and hexadecimal (0-9 and A-F). Because computers process everything in binary internally, reading hex or binary values is a routine part of debugging and inspecting data.
This tool is backed by JavaScript BigInt, so arbitrarily large integers (beyond 2^53) are converted exactly, without the precision loss you get from ordinary calculators. The number you enter never leaves your browser.
Hexadecimal input accepts both uppercase and lowercase letters. For readability, results are grouped every 4 digits for binary, 3 for octal, and 3 or 2 for decimal and hexadecimal (copying always yields the plain value).
FAQ
Can I convert numbers with decimals?
This tool supports integers only. Input containing a decimal point is rejected with an error message.
Are huge numbers beyond 2^53 converted exactly?
Yes. The tool is backed by BigInt, so arbitrarily large integers are converted without precision loss.
Can I enter hexadecimal in uppercase or lowercase?
Yes. Both A-F and a-f are accepted, and results are displayed in uppercase.
Is my number sent to a server?
No. All conversion happens locally in your browser.
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All processing happens in your browser. Your files are never uploaded.
Did you know?
Computers process all data in binary. Hexadecimal represents 4 binary digits as one character, which is why it appears in memory addresses.